Main:z from

Percentage Accurate: 91.5% → 98.8%
Time: 12.5s
Alternatives: 18
Speedup: 0.6×

Specification

?
\[\begin{array}{l} \\ \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+
  (+
   (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
   (- (sqrt (+ z 1.0)) (sqrt z)))
  (- (sqrt (+ t 1.0)) (sqrt t))))
double code(double x, double y, double z, double t) {
	return (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y, z, t)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + (sqrt((z + 1.0d0)) - sqrt(z))) + (sqrt((t + 1.0d0)) - sqrt(t))
end function
public static double code(double x, double y, double z, double t) {
	return (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + (Math.sqrt((z + 1.0)) - Math.sqrt(z))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
}
def code(x, y, z, t):
	return (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + (math.sqrt((z + 1.0)) - math.sqrt(z))) + (math.sqrt((t + 1.0)) - math.sqrt(t))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + Float64(sqrt(Float64(z + 1.0)) - sqrt(z))) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)))
end
function tmp = code(x, y, z, t)
	tmp = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
\end{array}

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 18 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 91.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+
  (+
   (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
   (- (sqrt (+ z 1.0)) (sqrt z)))
  (- (sqrt (+ t 1.0)) (sqrt t))))
double code(double x, double y, double z, double t) {
	return (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y, z, t)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + (sqrt((z + 1.0d0)) - sqrt(z))) + (sqrt((t + 1.0d0)) - sqrt(t))
end function
public static double code(double x, double y, double z, double t) {
	return (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + (Math.sqrt((z + 1.0)) - Math.sqrt(z))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
}
def code(x, y, z, t):
	return (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + (math.sqrt((z + 1.0)) - math.sqrt(z))) + (math.sqrt((t + 1.0)) - math.sqrt(t))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + Float64(sqrt(Float64(z + 1.0)) - sqrt(z))) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)))
end
function tmp = code(x, y, z, t)
	tmp = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
\end{array}

Alternative 1: 98.8% accurate, 0.3× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ t_4 := \sqrt{1 + x}\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_1\right) + t\_2\\ \mathbf{elif}\;t\_3 \leq 2.0002:\\ \;\;\;\;\left(t\_4 + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(\left(t\_4 + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
        (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
        (t_3
         (+
          (+
           (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
           t_1)
          t_2))
        (t_4 (sqrt (+ 1.0 x))))
   (if (<= t_3 5e-5)
     (+ (+ (fma 0.5 (/ 1.0 (sqrt x)) (* 0.5 (/ 1.0 (sqrt y)))) t_1) t_2)
     (if (<= t_3 2.0002)
       (-
        (+
         t_4
         (fma 0.5 (/ 1.0 (sqrt z)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))))
        (sqrt x))
       (+ (+ (- (- (+ t_4 1.0) (sqrt x)) (sqrt y)) t_1) t_2)))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((z + 1.0)) - sqrt(z);
	double t_2 = sqrt((t + 1.0)) - sqrt(t);
	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
	double t_4 = sqrt((1.0 + x));
	double tmp;
	if (t_3 <= 5e-5) {
		tmp = (fma(0.5, (1.0 / sqrt(x)), (0.5 * (1.0 / sqrt(y)))) + t_1) + t_2;
	} else if (t_3 <= 2.0002) {
		tmp = (t_4 + fma(0.5, (1.0 / sqrt(z)), (1.0 / (sqrt(y) + sqrt((1.0 + y)))))) - sqrt(x);
	} else {
		tmp = ((((t_4 + 1.0) - sqrt(x)) - sqrt(y)) + t_1) + t_2;
	}
	return tmp;
}
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
	t_4 = sqrt(Float64(1.0 + x))
	tmp = 0.0
	if (t_3 <= 5e-5)
		tmp = Float64(Float64(fma(0.5, Float64(1.0 / sqrt(x)), Float64(0.5 * Float64(1.0 / sqrt(y)))) + t_1) + t_2);
	elseif (t_3 <= 2.0002)
		tmp = Float64(Float64(t_4 + fma(0.5, Float64(1.0 / sqrt(z)), Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y)))))) - sqrt(x));
	else
		tmp = Float64(Float64(Float64(Float64(Float64(t_4 + 1.0) - sqrt(x)) - sqrt(y)) + t_1) + t_2);
	end
	return tmp
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, Block[{t$95$4 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], If[LessEqual[t$95$3, 2.0002], N[(N[(t$95$4 + N[(0.5 * N[(1.0 / N[Sqrt[z], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(N[(t$95$4 + 1.0), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := \sqrt{z + 1} - \sqrt{z}\\
t_2 := \sqrt{t + 1} - \sqrt{t}\\
t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
t_4 := \sqrt{1 + x}\\
\mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_1\right) + t\_2\\

\mathbf{elif}\;t\_3 \leq 2.0002:\\
\;\;\;\;\left(t\_4 + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\

\mathbf{else}:\\
\;\;\;\;\left(\left(\left(\left(t\_4 + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

    1. Initial program 6.5%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Taylor expanded in y around inf

      \[\leadsto \left(\color{blue}{\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-commutativeN/A

        \[\leadsto \left(\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{y}} + \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. *-commutativeN/A

        \[\leadsto \left(\left(\left(\sqrt{\frac{1}{y}} \cdot \frac{1}{2} + \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lower-fma.f64N/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\sqrt{\frac{1}{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. sqrt-divN/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{\sqrt{1}}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. metadata-evalN/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lower-/.f64N/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. +-commutativeN/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. +-commutativeN/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      12. lower-+.f64N/A

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      13. lift-sqrt.f646.5

        \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Applied rewrites6.5%

      \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Taylor expanded in x around inf

      \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Step-by-step derivation
      1. lower-fma.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \sqrt{\frac{1}{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. sqrt-divN/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{\sqrt{1}}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-evalN/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lower-/.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. lift-sqrt.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. lower-*.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. sqrt-divN/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. metadata-evalN/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. lift-sqrt.f64N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. lift-/.f6495.6

        \[\leadsto \left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Applied rewrites95.6%

      \[\leadsto \left(\mathsf{fma}\left(0.5, \color{blue}{\frac{1}{\sqrt{x}}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

    if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2.00019999999999998

    1. Initial program 95.8%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutativeN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. flip--N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lower-/.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Applied rewrites96.1%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
    5. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
    6. Applied rewrites11.1%

      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
    7. Taylor expanded in z around inf

      \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]
    8. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x} \]
    9. Applied rewrites99.4%

      \[\leadsto \left(\sqrt{1 + x} + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]

    if 2.00019999999999998 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

    1. Initial program 98.4%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Taylor expanded in y around 0

      \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Step-by-step derivation
      1. associate--r+N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lower--.f64N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lower--.f64N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. lower-+.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. lower-+.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. lift-sqrt.f6498.2

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Applied rewrites98.2%

      \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 2: 98.0% accurate, 0.3× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\ \mathbf{elif}\;t\_3 \leq 2.0002:\\ \;\;\;\;\left(\sqrt{1 + x} + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
        (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
        (t_3
         (+
          (+
           (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
           t_1)
          t_2)))
   (if (<= t_3 5e-5)
     (+ (+ (* 0.5 (/ 1.0 (sqrt x))) t_1) t_2)
     (if (<= t_3 2.0002)
       (-
        (+
         (sqrt (+ 1.0 x))
         (fma 0.5 (/ 1.0 (sqrt z)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))))
        (sqrt x))
       (+ (+ (- (- 2.0 (sqrt x)) (sqrt y)) t_1) t_2)))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((z + 1.0)) - sqrt(z);
	double t_2 = sqrt((t + 1.0)) - sqrt(t);
	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
	double tmp;
	if (t_3 <= 5e-5) {
		tmp = ((0.5 * (1.0 / sqrt(x))) + t_1) + t_2;
	} else if (t_3 <= 2.0002) {
		tmp = (sqrt((1.0 + x)) + fma(0.5, (1.0 / sqrt(z)), (1.0 / (sqrt(y) + sqrt((1.0 + y)))))) - sqrt(x);
	} else {
		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + t_1) + t_2;
	}
	return tmp;
}
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
	tmp = 0.0
	if (t_3 <= 5e-5)
		tmp = Float64(Float64(Float64(0.5 * Float64(1.0 / sqrt(x))) + t_1) + t_2);
	elseif (t_3 <= 2.0002)
		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + fma(0.5, Float64(1.0 / sqrt(z)), Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y)))))) - sqrt(x));
	else
		tmp = Float64(Float64(Float64(Float64(2.0 - sqrt(x)) - sqrt(y)) + t_1) + t_2);
	end
	return tmp
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], If[LessEqual[t$95$3, 2.0002], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[z], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := \sqrt{z + 1} - \sqrt{z}\\
t_2 := \sqrt{t + 1} - \sqrt{t}\\
t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
\mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\

\mathbf{elif}\;t\_3 \leq 2.0002:\\
\;\;\;\;\left(\sqrt{1 + x} + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\

\mathbf{else}:\\
\;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

    1. Initial program 6.5%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutativeN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. flip--N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lower-/.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Applied rewrites6.5%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lift--.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lift-*.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{\color{blue}{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \sqrt{\color{blue}{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \color{blue}{\sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. rem-square-sqrtN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. lift-*.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y}} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \sqrt{y} \cdot \color{blue}{\sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      12. rem-square-sqrtN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      13. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      14. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{\color{blue}{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      15. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      16. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y + 1} + \color{blue}{\sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      17. div-subN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Applied rewrites6.5%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Taylor expanded in y around inf

      \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lift-sqrt.f646.5

        \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Applied rewrites6.5%

      \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    9. Taylor expanded in x around inf

      \[\leadsto \left(\frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    10. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. sqrt-divN/A

        \[\leadsto \left(\frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-evalN/A

        \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lower-/.f64N/A

        \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. lift-sqrt.f6481.7

        \[\leadsto \left(0.5 \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    11. Applied rewrites81.7%

      \[\leadsto \left(0.5 \cdot \color{blue}{\frac{1}{\sqrt{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

    if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2.00019999999999998

    1. Initial program 95.8%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lift-+.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutativeN/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. flip--N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lower-/.f64N/A

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Applied rewrites96.1%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in t around inf

      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
    5. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
    6. Applied rewrites11.1%

      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
    7. Taylor expanded in z around inf

      \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]
    8. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x} \]
    9. Applied rewrites99.4%

      \[\leadsto \left(\sqrt{1 + x} + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]

    if 2.00019999999999998 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

    1. Initial program 98.4%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Taylor expanded in y around 0

      \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Step-by-step derivation
      1. associate--r+N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. lower--.f64N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. lower--.f64N/A

        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. lower-+.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. +-commutativeN/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. lower-+.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. lift-sqrt.f64N/A

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. lift-sqrt.f6498.2

        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Applied rewrites98.2%

      \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Taylor expanded in x around 0

      \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Step-by-step derivation
      1. Applied rewrites98.2%

        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Recombined 3 regimes into one program.
    8. Add Preprocessing

    Alternative 3: 98.0% accurate, 0.3× speedup?

    \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ t_4 := \sqrt{1 + x}\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\ \mathbf{elif}\;t\_3 \leq 2.0002:\\ \;\;\;\;\left(t\_4 + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(\left(t\_4 + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\ \end{array} \end{array} \]
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    (FPCore (x y z t)
     :precision binary64
     (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
            (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
            (t_3
             (+
              (+
               (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
               t_1)
              t_2))
            (t_4 (sqrt (+ 1.0 x))))
       (if (<= t_3 5e-5)
         (+ (+ (* 0.5 (/ 1.0 (sqrt x))) t_1) t_2)
         (if (<= t_3 2.0002)
           (-
            (+
             t_4
             (fma 0.5 (/ 1.0 (sqrt z)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))))
            (sqrt x))
           (+ (+ (- (- (+ t_4 1.0) (sqrt x)) (sqrt y)) t_1) t_2)))))
    assert(x < y && y < z && z < t);
    double code(double x, double y, double z, double t) {
    	double t_1 = sqrt((z + 1.0)) - sqrt(z);
    	double t_2 = sqrt((t + 1.0)) - sqrt(t);
    	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
    	double t_4 = sqrt((1.0 + x));
    	double tmp;
    	if (t_3 <= 5e-5) {
    		tmp = ((0.5 * (1.0 / sqrt(x))) + t_1) + t_2;
    	} else if (t_3 <= 2.0002) {
    		tmp = (t_4 + fma(0.5, (1.0 / sqrt(z)), (1.0 / (sqrt(y) + sqrt((1.0 + y)))))) - sqrt(x);
    	} else {
    		tmp = ((((t_4 + 1.0) - sqrt(x)) - sqrt(y)) + t_1) + t_2;
    	}
    	return tmp;
    }
    
    x, y, z, t = sort([x, y, z, t])
    function code(x, y, z, t)
    	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
    	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
    	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
    	t_4 = sqrt(Float64(1.0 + x))
    	tmp = 0.0
    	if (t_3 <= 5e-5)
    		tmp = Float64(Float64(Float64(0.5 * Float64(1.0 / sqrt(x))) + t_1) + t_2);
    	elseif (t_3 <= 2.0002)
    		tmp = Float64(Float64(t_4 + fma(0.5, Float64(1.0 / sqrt(z)), Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y)))))) - sqrt(x));
    	else
    		tmp = Float64(Float64(Float64(Float64(Float64(t_4 + 1.0) - sqrt(x)) - sqrt(y)) + t_1) + t_2);
    	end
    	return tmp
    end
    
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, Block[{t$95$4 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], If[LessEqual[t$95$3, 2.0002], N[(N[(t$95$4 + N[(0.5 * N[(1.0 / N[Sqrt[z], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(N[(t$95$4 + 1.0), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]]
    
    \begin{array}{l}
    [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
    \\
    \begin{array}{l}
    t_1 := \sqrt{z + 1} - \sqrt{z}\\
    t_2 := \sqrt{t + 1} - \sqrt{t}\\
    t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
    t_4 := \sqrt{1 + x}\\
    \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
    \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\
    
    \mathbf{elif}\;t\_3 \leq 2.0002:\\
    \;\;\;\;\left(t\_4 + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\left(\left(\left(t\_4 + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

      1. Initial program 6.5%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. +-commutativeN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. flip--N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lower-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Applied rewrites6.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-*.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{\color{blue}{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \sqrt{\color{blue}{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \color{blue}{\sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        8. rem-square-sqrtN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        9. lift-*.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        10. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y}} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        11. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \sqrt{y} \cdot \color{blue}{\sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        12. rem-square-sqrtN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        13. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        14. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{\color{blue}{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        15. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        16. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y + 1} + \color{blue}{\sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        17. div-subN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. Applied rewrites6.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. Taylor expanded in y around inf

        \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-+.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f646.5

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. Applied rewrites6.5%

        \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. Taylor expanded in x around inf

        \[\leadsto \left(\frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. Step-by-step derivation
        1. lower-*.f64N/A

          \[\leadsto \left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. sqrt-divN/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. metadata-evalN/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lower-/.f64N/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lift-sqrt.f6481.7

          \[\leadsto \left(0.5 \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. Applied rewrites81.7%

        \[\leadsto \left(0.5 \cdot \color{blue}{\frac{1}{\sqrt{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

      if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2.00019999999999998

      1. Initial program 95.8%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. +-commutativeN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. flip--N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lower-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Applied rewrites96.1%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Taylor expanded in t around inf

        \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
      5. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
      6. Applied rewrites11.1%

        \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
      7. Taylor expanded in z around inf

        \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]
      8. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \left(\frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x} \]
      9. Applied rewrites99.4%

        \[\leadsto \left(\sqrt{1 + x} + \mathsf{fma}\left(0.5, \frac{1}{\sqrt{z}}, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\sqrt{x}} \]

      if 2.00019999999999998 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

      1. Initial program 98.4%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Taylor expanded in y around 0

        \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Step-by-step derivation
        1. associate--r+N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lower--.f64N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lower--.f64N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lower-+.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        8. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        9. lower-+.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        10. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        11. lift-sqrt.f6498.2

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Applied rewrites98.2%

        \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    3. Recombined 3 regimes into one program.
    4. Add Preprocessing

    Alternative 4: 97.1% accurate, 0.3× speedup?

    \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{t + 1} - \sqrt{t}\\ t_2 := \sqrt{z + 1} - \sqrt{z}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_2\right) + t\_1\\ t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_2\right) + t\_1\\ \mathbf{elif}\;t\_3 \leq 2:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \mathbf{elif}\;t\_3 \leq 3.0001:\\ \;\;\;\;\left(t\_4 + t\_2\right) + 0.5 \cdot \frac{1}{\sqrt{t}}\\ \mathbf{else}:\\ \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_1\\ \end{array} \end{array} \]
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    (FPCore (x y z t)
     :precision binary64
     (let* ((t_1 (- (sqrt (+ t 1.0)) (sqrt t)))
            (t_2 (- (sqrt (+ z 1.0)) (sqrt z)))
            (t_3
             (+
              (+
               (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
               t_2)
              t_1))
            (t_4 (- (- 2.0 (sqrt x)) (sqrt y))))
       (if (<= t_3 5e-5)
         (+ (+ (* 0.5 (/ 1.0 (sqrt x))) t_2) t_1)
         (if (<= t_3 2.0)
           (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))
           (if (<= t_3 3.0001)
             (+ (+ t_4 t_2) (* 0.5 (/ 1.0 (sqrt t))))
             (+ (+ t_4 (- 1.0 (sqrt z))) t_1))))))
    assert(x < y && y < z && z < t);
    double code(double x, double y, double z, double t) {
    	double t_1 = sqrt((t + 1.0)) - sqrt(t);
    	double t_2 = sqrt((z + 1.0)) - sqrt(z);
    	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_2) + t_1;
    	double t_4 = (2.0 - sqrt(x)) - sqrt(y);
    	double tmp;
    	if (t_3 <= 5e-5) {
    		tmp = ((0.5 * (1.0 / sqrt(x))) + t_2) + t_1;
    	} else if (t_3 <= 2.0) {
    		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
    	} else if (t_3 <= 3.0001) {
    		tmp = (t_4 + t_2) + (0.5 * (1.0 / sqrt(t)));
    	} else {
    		tmp = (t_4 + (1.0 - sqrt(z))) + t_1;
    	}
    	return tmp;
    }
    
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    module fmin_fmax_functions
        implicit none
        private
        public fmax
        public fmin
    
        interface fmax
            module procedure fmax88
            module procedure fmax44
            module procedure fmax84
            module procedure fmax48
        end interface
        interface fmin
            module procedure fmin88
            module procedure fmin44
            module procedure fmin84
            module procedure fmin48
        end interface
    contains
        real(8) function fmax88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(4) function fmax44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
        end function
        real(8) function fmax84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmax48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
        end function
        real(8) function fmin88(x, y) result (res)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(4) function fmin44(x, y) result (res)
            real(4), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
        end function
        real(8) function fmin84(x, y) result(res)
            real(8), intent (in) :: x
            real(4), intent (in) :: y
            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
        end function
        real(8) function fmin48(x, y) result(res)
            real(4), intent (in) :: x
            real(8), intent (in) :: y
            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
        end function
    end module
    
    real(8) function code(x, y, z, t)
    use fmin_fmax_functions
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        real(8), intent (in) :: t
        real(8) :: t_1
        real(8) :: t_2
        real(8) :: t_3
        real(8) :: t_4
        real(8) :: tmp
        t_1 = sqrt((t + 1.0d0)) - sqrt(t)
        t_2 = sqrt((z + 1.0d0)) - sqrt(z)
        t_3 = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + t_2) + t_1
        t_4 = (2.0d0 - sqrt(x)) - sqrt(y)
        if (t_3 <= 5d-5) then
            tmp = ((0.5d0 * (1.0d0 / sqrt(x))) + t_2) + t_1
        else if (t_3 <= 2.0d0) then
            tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
        else if (t_3 <= 3.0001d0) then
            tmp = (t_4 + t_2) + (0.5d0 * (1.0d0 / sqrt(t)))
        else
            tmp = (t_4 + (1.0d0 - sqrt(z))) + t_1
        end if
        code = tmp
    end function
    
    assert x < y && y < z && z < t;
    public static double code(double x, double y, double z, double t) {
    	double t_1 = Math.sqrt((t + 1.0)) - Math.sqrt(t);
    	double t_2 = Math.sqrt((z + 1.0)) - Math.sqrt(z);
    	double t_3 = (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + t_2) + t_1;
    	double t_4 = (2.0 - Math.sqrt(x)) - Math.sqrt(y);
    	double tmp;
    	if (t_3 <= 5e-5) {
    		tmp = ((0.5 * (1.0 / Math.sqrt(x))) + t_2) + t_1;
    	} else if (t_3 <= 2.0) {
    		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
    	} else if (t_3 <= 3.0001) {
    		tmp = (t_4 + t_2) + (0.5 * (1.0 / Math.sqrt(t)));
    	} else {
    		tmp = (t_4 + (1.0 - Math.sqrt(z))) + t_1;
    	}
    	return tmp;
    }
    
    [x, y, z, t] = sort([x, y, z, t])
    def code(x, y, z, t):
    	t_1 = math.sqrt((t + 1.0)) - math.sqrt(t)
    	t_2 = math.sqrt((z + 1.0)) - math.sqrt(z)
    	t_3 = (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + t_2) + t_1
    	t_4 = (2.0 - math.sqrt(x)) - math.sqrt(y)
    	tmp = 0
    	if t_3 <= 5e-5:
    		tmp = ((0.5 * (1.0 / math.sqrt(x))) + t_2) + t_1
    	elif t_3 <= 2.0:
    		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
    	elif t_3 <= 3.0001:
    		tmp = (t_4 + t_2) + (0.5 * (1.0 / math.sqrt(t)))
    	else:
    		tmp = (t_4 + (1.0 - math.sqrt(z))) + t_1
    	return tmp
    
    x, y, z, t = sort([x, y, z, t])
    function code(x, y, z, t)
    	t_1 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
    	t_2 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
    	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_2) + t_1)
    	t_4 = Float64(Float64(2.0 - sqrt(x)) - sqrt(y))
    	tmp = 0.0
    	if (t_3 <= 5e-5)
    		tmp = Float64(Float64(Float64(0.5 * Float64(1.0 / sqrt(x))) + t_2) + t_1);
    	elseif (t_3 <= 2.0)
    		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
    	elseif (t_3 <= 3.0001)
    		tmp = Float64(Float64(t_4 + t_2) + Float64(0.5 * Float64(1.0 / sqrt(t))));
    	else
    		tmp = Float64(Float64(t_4 + Float64(1.0 - sqrt(z))) + t_1);
    	end
    	return tmp
    end
    
    x, y, z, t = num2cell(sort([x, y, z, t])){:}
    function tmp_2 = code(x, y, z, t)
    	t_1 = sqrt((t + 1.0)) - sqrt(t);
    	t_2 = sqrt((z + 1.0)) - sqrt(z);
    	t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_2) + t_1;
    	t_4 = (2.0 - sqrt(x)) - sqrt(y);
    	tmp = 0.0;
    	if (t_3 <= 5e-5)
    		tmp = ((0.5 * (1.0 / sqrt(x))) + t_2) + t_1;
    	elseif (t_3 <= 2.0)
    		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
    	elseif (t_3 <= 3.0001)
    		tmp = (t_4 + t_2) + (0.5 * (1.0 / sqrt(t)));
    	else
    		tmp = (t_4 + (1.0 - sqrt(z))) + t_1;
    	end
    	tmp_2 = tmp;
    end
    
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$1), $MachinePrecision]}, Block[{t$95$4 = N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$1), $MachinePrecision], If[LessEqual[t$95$3, 2.0], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$3, 3.0001], N[(N[(t$95$4 + t$95$2), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$4 + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision]]]]]]]]
    
    \begin{array}{l}
    [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
    \\
    \begin{array}{l}
    t_1 := \sqrt{t + 1} - \sqrt{t}\\
    t_2 := \sqrt{z + 1} - \sqrt{z}\\
    t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_2\right) + t\_1\\
    t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\
    \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
    \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_2\right) + t\_1\\
    
    \mathbf{elif}\;t\_3 \leq 2:\\
    \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
    
    \mathbf{elif}\;t\_3 \leq 3.0001:\\
    \;\;\;\;\left(t\_4 + t\_2\right) + 0.5 \cdot \frac{1}{\sqrt{t}}\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 4 regimes
    2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

      1. Initial program 6.5%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. +-commutativeN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. flip--N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lower-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Applied rewrites6.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-*.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{\color{blue}{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \sqrt{\color{blue}{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \color{blue}{\sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        8. rem-square-sqrtN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        9. lift-*.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        10. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y}} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        11. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \sqrt{y} \cdot \color{blue}{\sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        12. rem-square-sqrtN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        13. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        14. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{\color{blue}{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        15. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        16. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y + 1} + \color{blue}{\sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        17. div-subN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. Applied rewrites6.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. Taylor expanded in y around inf

        \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      7. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-+.f64N/A

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f646.5

          \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      8. Applied rewrites6.5%

        \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      9. Taylor expanded in x around inf

        \[\leadsto \left(\frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      10. Step-by-step derivation
        1. lower-*.f64N/A

          \[\leadsto \left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. sqrt-divN/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. metadata-evalN/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lower-/.f64N/A

          \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lift-sqrt.f6481.7

          \[\leadsto \left(0.5 \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      11. Applied rewrites81.7%

        \[\leadsto \left(0.5 \cdot \color{blue}{\frac{1}{\sqrt{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

      if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2

      1. Initial program 96.5%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lift-+.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. +-commutativeN/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. flip--N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lower-/.f64N/A

          \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Applied rewrites96.8%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Taylor expanded in t around inf

        \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
      5. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
      6. Applied rewrites8.9%

        \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
      7. Taylor expanded in z around inf

        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
      8. Step-by-step derivation
        1. lower--.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        2. lower-+.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        3. lift-sqrt.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        4. lift-+.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        5. lift-sqrt.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        6. lift-sqrt.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        7. lift-+.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        8. lift-+.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        9. lift-/.f64N/A

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
        10. lift-sqrt.f6498.1

          \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
      9. Applied rewrites98.1%

        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]

      if 2 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 3.00010000000000021

      1. Initial program 96.6%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Taylor expanded in y around 0

        \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. Step-by-step derivation
        1. associate--r+N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. lower--.f64N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. lower--.f64N/A

          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. lower-+.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        7. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        8. +-commutativeN/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        9. lower-+.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        10. lift-sqrt.f64N/A

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        11. lift-sqrt.f6496.4

          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. Applied rewrites96.4%

        \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. Taylor expanded in x around 0

        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. Step-by-step derivation
        1. Applied rewrites96.4%

          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. Taylor expanded in t around inf

          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{t}}} \]
        3. Step-by-step derivation
          1. lower-*.f64N/A

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{t}}} \]
          2. sqrt-divN/A

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{\sqrt{1}}{\color{blue}{\sqrt{t}}} \]
          3. metadata-evalN/A

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{1}{\sqrt{\color{blue}{t}}} \]
          4. lower-/.f64N/A

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{1}{\color{blue}{\sqrt{t}}} \]
          5. lift-sqrt.f6497.9

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + 0.5 \cdot \frac{1}{\sqrt{t}} \]
        4. Applied rewrites97.9%

          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \color{blue}{0.5 \cdot \frac{1}{\sqrt{t}}} \]

        if 3.00010000000000021 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

        1. Initial program 99.5%

          \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. Taylor expanded in y around 0

          \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        3. Step-by-step derivation
          1. associate--r+N/A

            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          2. lower--.f64N/A

            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          3. lower--.f64N/A

            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          4. +-commutativeN/A

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          5. lower-+.f64N/A

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          6. +-commutativeN/A

            \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          7. lift-sqrt.f64N/A

            \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          8. +-commutativeN/A

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          9. lower-+.f64N/A

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          10. lift-sqrt.f64N/A

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          11. lift-sqrt.f6499.5

            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        4. Applied rewrites99.5%

          \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        5. Taylor expanded in x around 0

          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        6. Step-by-step derivation
          1. Applied rewrites99.5%

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          2. Taylor expanded in z around 0

            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          3. Step-by-step derivation
            1. Applied rewrites98.9%

              \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          4. Recombined 4 regimes into one program.
          5. Add Preprocessing

          Alternative 5: 96.8% accurate, 0.6× speedup?

          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y + 1}\\ t_2 := \sqrt{z + 1} - \sqrt{z}\\ t_3 := \sqrt{t + 1} - \sqrt{t}\\ \mathbf{if}\;x \leq 175000000:\\ \;\;\;\;\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{t\_1 \cdot t\_1 - \sqrt{y} \cdot \sqrt{y}}{t\_1 + \sqrt{y}}\right) + t\_2\right) + t\_3\\ \mathbf{else}:\\ \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_2\right) + t\_3\\ \end{array} \end{array} \]
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (sqrt (+ y 1.0)))
                  (t_2 (- (sqrt (+ z 1.0)) (sqrt z)))
                  (t_3 (- (sqrt (+ t 1.0)) (sqrt t))))
             (if (<= x 175000000.0)
               (+
                (+
                 (+
                  (- (sqrt (+ x 1.0)) (sqrt x))
                  (/ (- (* t_1 t_1) (* (sqrt y) (sqrt y))) (+ t_1 (sqrt y))))
                 t_2)
                t_3)
               (+ (+ (fma 0.5 (/ 1.0 (sqrt x)) (* 0.5 (/ 1.0 (sqrt y)))) t_2) t_3))))
          assert(x < y && y < z && z < t);
          double code(double x, double y, double z, double t) {
          	double t_1 = sqrt((y + 1.0));
          	double t_2 = sqrt((z + 1.0)) - sqrt(z);
          	double t_3 = sqrt((t + 1.0)) - sqrt(t);
          	double tmp;
          	if (x <= 175000000.0) {
          		tmp = (((sqrt((x + 1.0)) - sqrt(x)) + (((t_1 * t_1) - (sqrt(y) * sqrt(y))) / (t_1 + sqrt(y)))) + t_2) + t_3;
          	} else {
          		tmp = (fma(0.5, (1.0 / sqrt(x)), (0.5 * (1.0 / sqrt(y)))) + t_2) + t_3;
          	}
          	return tmp;
          }
          
          x, y, z, t = sort([x, y, z, t])
          function code(x, y, z, t)
          	t_1 = sqrt(Float64(y + 1.0))
          	t_2 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
          	t_3 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
          	tmp = 0.0
          	if (x <= 175000000.0)
          		tmp = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(Float64(Float64(t_1 * t_1) - Float64(sqrt(y) * sqrt(y))) / Float64(t_1 + sqrt(y)))) + t_2) + t_3);
          	else
          		tmp = Float64(Float64(fma(0.5, Float64(1.0 / sqrt(x)), Float64(0.5 * Float64(1.0 / sqrt(y)))) + t_2) + t_3);
          	end
          	return tmp
          end
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          code[x_, y_, z_, t_] := Block[{t$95$1 = N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 175000000.0], N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(t$95$1 * t$95$1), $MachinePrecision] - N[(N[Sqrt[y], $MachinePrecision] * N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$1 + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$3), $MachinePrecision], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$3), $MachinePrecision]]]]]
          
          \begin{array}{l}
          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
          \\
          \begin{array}{l}
          t_1 := \sqrt{y + 1}\\
          t_2 := \sqrt{z + 1} - \sqrt{z}\\
          t_3 := \sqrt{t + 1} - \sqrt{t}\\
          \mathbf{if}\;x \leq 175000000:\\
          \;\;\;\;\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{t\_1 \cdot t\_1 - \sqrt{y} \cdot \sqrt{y}}{t\_1 + \sqrt{y}}\right) + t\_2\right) + t\_3\\
          
          \mathbf{else}:\\
          \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_2\right) + t\_3\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if x < 1.75e8

            1. Initial program 96.7%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. +-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. flip--N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Applied rewrites96.9%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

            if 1.75e8 < x

            1. Initial program 6.4%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Taylor expanded in y around inf

              \[\leadsto \left(\color{blue}{\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. +-commutativeN/A

                \[\leadsto \left(\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{y}} + \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. *-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{\frac{1}{y}} \cdot \frac{1}{2} + \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-fma.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\sqrt{\frac{1}{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. sqrt-divN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{\sqrt{1}}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. metadata-evalN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              12. lower-+.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              13. lift-sqrt.f646.4

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Applied rewrites6.4%

              \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Taylor expanded in x around inf

              \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            6. Step-by-step derivation
              1. lower-fma.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \sqrt{\frac{1}{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{\sqrt{1}}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-/.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. lower-*.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-/.f6495.7

                \[\leadsto \left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            7. Applied rewrites95.7%

              \[\leadsto \left(\mathsf{fma}\left(0.5, \color{blue}{\frac{1}{\sqrt{x}}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          3. Recombined 2 regimes into one program.
          4. Add Preprocessing

          Alternative 6: 96.8% accurate, 0.4× speedup?

          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y + 1}\\ t_2 := \sqrt{z + 1} - \sqrt{z}\\ t_3 := t\_1 + \sqrt{y}\\ t_4 := \sqrt{x + 1} - \sqrt{x}\\ t_5 := \sqrt{t + 1} - \sqrt{t}\\ \mathbf{if}\;\left(\left(t\_4 + \left(t\_1 - \sqrt{y}\right)\right) + t\_2\right) + t\_5 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_2\right) + t\_5\\ \mathbf{else}:\\ \;\;\;\;\left(\left(t\_4 + \left(\frac{y + 1}{t\_3} - \frac{y}{t\_3}\right)\right) + t\_2\right) + t\_5\\ \end{array} \end{array} \]
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (sqrt (+ y 1.0)))
                  (t_2 (- (sqrt (+ z 1.0)) (sqrt z)))
                  (t_3 (+ t_1 (sqrt y)))
                  (t_4 (- (sqrt (+ x 1.0)) (sqrt x)))
                  (t_5 (- (sqrt (+ t 1.0)) (sqrt t))))
             (if (<= (+ (+ (+ t_4 (- t_1 (sqrt y))) t_2) t_5) 5e-5)
               (+ (+ (fma 0.5 (/ 1.0 (sqrt x)) (* 0.5 (/ 1.0 (sqrt y)))) t_2) t_5)
               (+ (+ (+ t_4 (- (/ (+ y 1.0) t_3) (/ y t_3))) t_2) t_5))))
          assert(x < y && y < z && z < t);
          double code(double x, double y, double z, double t) {
          	double t_1 = sqrt((y + 1.0));
          	double t_2 = sqrt((z + 1.0)) - sqrt(z);
          	double t_3 = t_1 + sqrt(y);
          	double t_4 = sqrt((x + 1.0)) - sqrt(x);
          	double t_5 = sqrt((t + 1.0)) - sqrt(t);
          	double tmp;
          	if ((((t_4 + (t_1 - sqrt(y))) + t_2) + t_5) <= 5e-5) {
          		tmp = (fma(0.5, (1.0 / sqrt(x)), (0.5 * (1.0 / sqrt(y)))) + t_2) + t_5;
          	} else {
          		tmp = ((t_4 + (((y + 1.0) / t_3) - (y / t_3))) + t_2) + t_5;
          	}
          	return tmp;
          }
          
          x, y, z, t = sort([x, y, z, t])
          function code(x, y, z, t)
          	t_1 = sqrt(Float64(y + 1.0))
          	t_2 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
          	t_3 = Float64(t_1 + sqrt(y))
          	t_4 = Float64(sqrt(Float64(x + 1.0)) - sqrt(x))
          	t_5 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
          	tmp = 0.0
          	if (Float64(Float64(Float64(t_4 + Float64(t_1 - sqrt(y))) + t_2) + t_5) <= 5e-5)
          		tmp = Float64(Float64(fma(0.5, Float64(1.0 / sqrt(x)), Float64(0.5 * Float64(1.0 / sqrt(y)))) + t_2) + t_5);
          	else
          		tmp = Float64(Float64(Float64(t_4 + Float64(Float64(Float64(y + 1.0) / t_3) - Float64(y / t_3))) + t_2) + t_5);
          	end
          	return tmp
          end
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          code[x_, y_, z_, t_] := Block[{t$95$1 = N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$1 + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$5 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(N[(t$95$4 + N[(t$95$1 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$5), $MachinePrecision], 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$5), $MachinePrecision], N[(N[(N[(t$95$4 + N[(N[(N[(y + 1.0), $MachinePrecision] / t$95$3), $MachinePrecision] - N[(y / t$95$3), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$5), $MachinePrecision]]]]]]]
          
          \begin{array}{l}
          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
          \\
          \begin{array}{l}
          t_1 := \sqrt{y + 1}\\
          t_2 := \sqrt{z + 1} - \sqrt{z}\\
          t_3 := t\_1 + \sqrt{y}\\
          t_4 := \sqrt{x + 1} - \sqrt{x}\\
          t_5 := \sqrt{t + 1} - \sqrt{t}\\
          \mathbf{if}\;\left(\left(t\_4 + \left(t\_1 - \sqrt{y}\right)\right) + t\_2\right) + t\_5 \leq 5 \cdot 10^{-5}:\\
          \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_2\right) + t\_5\\
          
          \mathbf{else}:\\
          \;\;\;\;\left(\left(t\_4 + \left(\frac{y + 1}{t\_3} - \frac{y}{t\_3}\right)\right) + t\_2\right) + t\_5\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

            1. Initial program 6.5%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Taylor expanded in y around inf

              \[\leadsto \left(\color{blue}{\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. +-commutativeN/A

                \[\leadsto \left(\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{y}} + \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. *-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{\frac{1}{y}} \cdot \frac{1}{2} + \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-fma.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\sqrt{\frac{1}{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. sqrt-divN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{\sqrt{1}}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. metadata-evalN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              12. lower-+.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              13. lift-sqrt.f646.5

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Applied rewrites6.5%

              \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Taylor expanded in x around inf

              \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            6. Step-by-step derivation
              1. lower-fma.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \sqrt{\frac{1}{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{\sqrt{1}}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-/.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. lower-*.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-/.f6495.6

                \[\leadsto \left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            7. Applied rewrites95.6%

              \[\leadsto \left(\mathsf{fma}\left(0.5, \color{blue}{\frac{1}{\sqrt{x}}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

            if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

            1. Initial program 96.7%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. +-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. flip--N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Applied rewrites96.9%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Step-by-step derivation
              1. lift-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-*.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{\color{blue}{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \sqrt{\color{blue}{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \color{blue}{\sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. rem-square-sqrtN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lift-*.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y}} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \sqrt{y} \cdot \color{blue}{\sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              12. rem-square-sqrtN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              13. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              14. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{\color{blue}{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              15. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              16. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y + 1} + \color{blue}{\sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              17. div-subN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Applied rewrites96.8%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          3. Recombined 2 regimes into one program.
          4. Add Preprocessing

          Alternative 7: 96.7% accurate, 0.5× speedup?

          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_1\right) + t\_2\\ \mathbf{else}:\\ \;\;\;\;t\_3\\ \end{array} \end{array} \]
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
                  (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
                  (t_3
                   (+
                    (+
                     (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
                     t_1)
                    t_2)))
             (if (<= t_3 5e-5)
               (+ (+ (fma 0.5 (/ 1.0 (sqrt x)) (* 0.5 (/ 1.0 (sqrt y)))) t_1) t_2)
               t_3)))
          assert(x < y && y < z && z < t);
          double code(double x, double y, double z, double t) {
          	double t_1 = sqrt((z + 1.0)) - sqrt(z);
          	double t_2 = sqrt((t + 1.0)) - sqrt(t);
          	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
          	double tmp;
          	if (t_3 <= 5e-5) {
          		tmp = (fma(0.5, (1.0 / sqrt(x)), (0.5 * (1.0 / sqrt(y)))) + t_1) + t_2;
          	} else {
          		tmp = t_3;
          	}
          	return tmp;
          }
          
          x, y, z, t = sort([x, y, z, t])
          function code(x, y, z, t)
          	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
          	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
          	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
          	tmp = 0.0
          	if (t_3 <= 5e-5)
          		tmp = Float64(Float64(fma(0.5, Float64(1.0 / sqrt(x)), Float64(0.5 * Float64(1.0 / sqrt(y)))) + t_1) + t_2);
          	else
          		tmp = t_3;
          	end
          	return tmp
          end
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], t$95$3]]]]
          
          \begin{array}{l}
          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
          \\
          \begin{array}{l}
          t_1 := \sqrt{z + 1} - \sqrt{z}\\
          t_2 := \sqrt{t + 1} - \sqrt{t}\\
          t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
          \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
          \;\;\;\;\left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + t\_1\right) + t\_2\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_3\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

            1. Initial program 6.5%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Taylor expanded in y around inf

              \[\leadsto \left(\color{blue}{\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. +-commutativeN/A

                \[\leadsto \left(\left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{y}} + \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. *-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{\frac{1}{y}} \cdot \frac{1}{2} + \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-fma.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\sqrt{\frac{1}{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. sqrt-divN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{\sqrt{1}}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. metadata-evalN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{x + 1}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              12. lower-+.f64N/A

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, \frac{1}{2}, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              13. lift-sqrt.f646.5

                \[\leadsto \left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Applied rewrites6.5%

              \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(\frac{1}{\sqrt{y}}, 0.5, \sqrt{1 + x}\right) - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Taylor expanded in x around inf

              \[\leadsto \left(\left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            6. Step-by-step derivation
              1. lower-fma.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \sqrt{\frac{1}{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{\sqrt{1}}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-/.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. lower-*.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \sqrt{\frac{1}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. sqrt-divN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. metadata-evalN/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lift-sqrt.f64N/A

                \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2}, \frac{1}{\sqrt{x}}, \frac{1}{2} \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-/.f6495.6

                \[\leadsto \left(\mathsf{fma}\left(0.5, \frac{1}{\sqrt{x}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            7. Applied rewrites95.6%

              \[\leadsto \left(\mathsf{fma}\left(0.5, \color{blue}{\frac{1}{\sqrt{x}}}, 0.5 \cdot \frac{1}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

            if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

            1. Initial program 96.7%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          3. Recombined 2 regimes into one program.
          4. Add Preprocessing

          Alternative 8: 96.7% accurate, 0.3× speedup?

          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\ \mathbf{elif}\;t\_3 \leq 2:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\ \end{array} \end{array} \]
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
                  (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
                  (t_3
                   (+
                    (+
                     (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
                     t_1)
                    t_2)))
             (if (<= t_3 5e-5)
               (+ (+ (* 0.5 (/ 1.0 (sqrt x))) t_1) t_2)
               (if (<= t_3 2.0)
                 (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))
                 (+ (+ (- (- 2.0 (sqrt x)) (sqrt y)) t_1) t_2)))))
          assert(x < y && y < z && z < t);
          double code(double x, double y, double z, double t) {
          	double t_1 = sqrt((z + 1.0)) - sqrt(z);
          	double t_2 = sqrt((t + 1.0)) - sqrt(t);
          	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
          	double tmp;
          	if (t_3 <= 5e-5) {
          		tmp = ((0.5 * (1.0 / sqrt(x))) + t_1) + t_2;
          	} else if (t_3 <= 2.0) {
          		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
          	} else {
          		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + t_1) + t_2;
          	}
          	return tmp;
          }
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(x, y, z, t)
          use fmin_fmax_functions
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              real(8), intent (in) :: t
              real(8) :: t_1
              real(8) :: t_2
              real(8) :: t_3
              real(8) :: tmp
              t_1 = sqrt((z + 1.0d0)) - sqrt(z)
              t_2 = sqrt((t + 1.0d0)) - sqrt(t)
              t_3 = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + t_1) + t_2
              if (t_3 <= 5d-5) then
                  tmp = ((0.5d0 * (1.0d0 / sqrt(x))) + t_1) + t_2
              else if (t_3 <= 2.0d0) then
                  tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
              else
                  tmp = (((2.0d0 - sqrt(x)) - sqrt(y)) + t_1) + t_2
              end if
              code = tmp
          end function
          
          assert x < y && y < z && z < t;
          public static double code(double x, double y, double z, double t) {
          	double t_1 = Math.sqrt((z + 1.0)) - Math.sqrt(z);
          	double t_2 = Math.sqrt((t + 1.0)) - Math.sqrt(t);
          	double t_3 = (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + t_1) + t_2;
          	double tmp;
          	if (t_3 <= 5e-5) {
          		tmp = ((0.5 * (1.0 / Math.sqrt(x))) + t_1) + t_2;
          	} else if (t_3 <= 2.0) {
          		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
          	} else {
          		tmp = (((2.0 - Math.sqrt(x)) - Math.sqrt(y)) + t_1) + t_2;
          	}
          	return tmp;
          }
          
          [x, y, z, t] = sort([x, y, z, t])
          def code(x, y, z, t):
          	t_1 = math.sqrt((z + 1.0)) - math.sqrt(z)
          	t_2 = math.sqrt((t + 1.0)) - math.sqrt(t)
          	t_3 = (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + t_1) + t_2
          	tmp = 0
          	if t_3 <= 5e-5:
          		tmp = ((0.5 * (1.0 / math.sqrt(x))) + t_1) + t_2
          	elif t_3 <= 2.0:
          		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
          	else:
          		tmp = (((2.0 - math.sqrt(x)) - math.sqrt(y)) + t_1) + t_2
          	return tmp
          
          x, y, z, t = sort([x, y, z, t])
          function code(x, y, z, t)
          	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
          	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
          	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
          	tmp = 0.0
          	if (t_3 <= 5e-5)
          		tmp = Float64(Float64(Float64(0.5 * Float64(1.0 / sqrt(x))) + t_1) + t_2);
          	elseif (t_3 <= 2.0)
          		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
          	else
          		tmp = Float64(Float64(Float64(Float64(2.0 - sqrt(x)) - sqrt(y)) + t_1) + t_2);
          	end
          	return tmp
          end
          
          x, y, z, t = num2cell(sort([x, y, z, t])){:}
          function tmp_2 = code(x, y, z, t)
          	t_1 = sqrt((z + 1.0)) - sqrt(z);
          	t_2 = sqrt((t + 1.0)) - sqrt(t);
          	t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
          	tmp = 0.0;
          	if (t_3 <= 5e-5)
          		tmp = ((0.5 * (1.0 / sqrt(x))) + t_1) + t_2;
          	elseif (t_3 <= 2.0)
          		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
          	else
          		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + t_1) + t_2;
          	end
          	tmp_2 = tmp;
          end
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, If[LessEqual[t$95$3, 5e-5], N[(N[(N[(0.5 * N[(1.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision], If[LessEqual[t$95$3, 2.0], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]
          
          \begin{array}{l}
          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
          \\
          \begin{array}{l}
          t_1 := \sqrt{z + 1} - \sqrt{z}\\
          t_2 := \sqrt{t + 1} - \sqrt{t}\\
          t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
          \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-5}:\\
          \;\;\;\;\left(0.5 \cdot \frac{1}{\sqrt{x}} + t\_1\right) + t\_2\\
          
          \mathbf{elif}\;t\_3 \leq 2:\\
          \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
          
          \mathbf{else}:\\
          \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + t\_1\right) + t\_2\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 5.00000000000000024e-5

            1. Initial program 6.5%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. +-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. flip--N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Applied rewrites6.5%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Step-by-step derivation
              1. lift-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-*.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1} \cdot \sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{\color{blue}{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\sqrt{y + 1}} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \sqrt{\color{blue}{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\sqrt{y + 1} \cdot \color{blue}{\sqrt{y + 1}} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. rem-square-sqrtN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lift-*.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y} \cdot \sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{\sqrt{y}} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \sqrt{y} \cdot \color{blue}{\sqrt{y}}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              12. rem-square-sqrtN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              13. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              14. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{\color{blue}{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              15. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\color{blue}{\sqrt{y + 1}} + \sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              16. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y + 1} + \color{blue}{\sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              17. div-subN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Applied rewrites6.5%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\frac{y + 1}{\sqrt{y + 1} + \sqrt{y}} - \frac{y}{\sqrt{y + 1} + \sqrt{y}}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            6. Taylor expanded in y around inf

              \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            7. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{\color{blue}{x}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-+.f64N/A

                \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-sqrt.f646.5

                \[\leadsto \left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            8. Applied rewrites6.5%

              \[\leadsto \left(\color{blue}{\left(\sqrt{1 + x} - \sqrt{x}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            9. Taylor expanded in x around inf

              \[\leadsto \left(\frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            10. Step-by-step derivation
              1. lower-*.f64N/A

                \[\leadsto \left(\frac{1}{2} \cdot \sqrt{\frac{1}{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. sqrt-divN/A

                \[\leadsto \left(\frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. metadata-evalN/A

                \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lower-/.f64N/A

                \[\leadsto \left(\frac{1}{2} \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lift-sqrt.f6481.7

                \[\leadsto \left(0.5 \cdot \frac{1}{\sqrt{x}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            11. Applied rewrites81.7%

              \[\leadsto \left(0.5 \cdot \color{blue}{\frac{1}{\sqrt{x}}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

            if 5.00000000000000024e-5 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2

            1. Initial program 96.5%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. lift--.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lift-+.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. +-commutativeN/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. flip--N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lower-/.f64N/A

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Applied rewrites96.8%

              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Taylor expanded in t around inf

              \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
            5. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
            6. Applied rewrites8.9%

              \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
            7. Taylor expanded in z around inf

              \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
            8. Step-by-step derivation
              1. lower--.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              2. lower-+.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              3. lift-sqrt.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              4. lift-+.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              5. lift-sqrt.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              6. lift-sqrt.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              7. lift-+.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              8. lift-+.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              9. lift-/.f64N/A

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              10. lift-sqrt.f6498.1

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
            9. Applied rewrites98.1%

              \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]

            if 2 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

            1. Initial program 97.2%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Taylor expanded in y around 0

              \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            3. Step-by-step derivation
              1. associate--r+N/A

                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. lower--.f64N/A

                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. lower--.f64N/A

                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. +-commutativeN/A

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. lower-+.f64N/A

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. +-commutativeN/A

                \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              7. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              8. +-commutativeN/A

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              9. lower-+.f64N/A

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              10. lift-sqrt.f64N/A

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              11. lift-sqrt.f6497.0

                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            4. Applied rewrites97.0%

              \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            5. Taylor expanded in x around 0

              \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            6. Step-by-step derivation
              1. Applied rewrites97.0%

                \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            7. Recombined 3 regimes into one program.
            8. Add Preprocessing

            Alternative 9: 92.8% accurate, 0.4× speedup?

            \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\ \mathbf{if}\;t\_3 \leq 2:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \mathbf{elif}\;t\_3 \leq 3.0001:\\ \;\;\;\;\left(t\_4 + t\_1\right) + 0.5 \cdot \frac{1}{\sqrt{t}}\\ \mathbf{else}:\\ \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_2\\ \end{array} \end{array} \]
            NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
            (FPCore (x y z t)
             :precision binary64
             (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
                    (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
                    (t_3
                     (+
                      (+
                       (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
                       t_1)
                      t_2))
                    (t_4 (- (- 2.0 (sqrt x)) (sqrt y))))
               (if (<= t_3 2.0)
                 (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))
                 (if (<= t_3 3.0001)
                   (+ (+ t_4 t_1) (* 0.5 (/ 1.0 (sqrt t))))
                   (+ (+ t_4 (- 1.0 (sqrt z))) t_2)))))
            assert(x < y && y < z && z < t);
            double code(double x, double y, double z, double t) {
            	double t_1 = sqrt((z + 1.0)) - sqrt(z);
            	double t_2 = sqrt((t + 1.0)) - sqrt(t);
            	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
            	double t_4 = (2.0 - sqrt(x)) - sqrt(y);
            	double tmp;
            	if (t_3 <= 2.0) {
            		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
            	} else if (t_3 <= 3.0001) {
            		tmp = (t_4 + t_1) + (0.5 * (1.0 / sqrt(t)));
            	} else {
            		tmp = (t_4 + (1.0 - sqrt(z))) + t_2;
            	}
            	return tmp;
            }
            
            NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
            module fmin_fmax_functions
                implicit none
                private
                public fmax
                public fmin
            
                interface fmax
                    module procedure fmax88
                    module procedure fmax44
                    module procedure fmax84
                    module procedure fmax48
                end interface
                interface fmin
                    module procedure fmin88
                    module procedure fmin44
                    module procedure fmin84
                    module procedure fmin48
                end interface
            contains
                real(8) function fmax88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(4) function fmax44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(8) function fmax84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmax48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                end function
                real(8) function fmin88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(4) function fmin44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(8) function fmin84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmin48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                end function
            end module
            
            real(8) function code(x, y, z, t)
            use fmin_fmax_functions
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8), intent (in) :: z
                real(8), intent (in) :: t
                real(8) :: t_1
                real(8) :: t_2
                real(8) :: t_3
                real(8) :: t_4
                real(8) :: tmp
                t_1 = sqrt((z + 1.0d0)) - sqrt(z)
                t_2 = sqrt((t + 1.0d0)) - sqrt(t)
                t_3 = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + t_1) + t_2
                t_4 = (2.0d0 - sqrt(x)) - sqrt(y)
                if (t_3 <= 2.0d0) then
                    tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
                else if (t_3 <= 3.0001d0) then
                    tmp = (t_4 + t_1) + (0.5d0 * (1.0d0 / sqrt(t)))
                else
                    tmp = (t_4 + (1.0d0 - sqrt(z))) + t_2
                end if
                code = tmp
            end function
            
            assert x < y && y < z && z < t;
            public static double code(double x, double y, double z, double t) {
            	double t_1 = Math.sqrt((z + 1.0)) - Math.sqrt(z);
            	double t_2 = Math.sqrt((t + 1.0)) - Math.sqrt(t);
            	double t_3 = (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + t_1) + t_2;
            	double t_4 = (2.0 - Math.sqrt(x)) - Math.sqrt(y);
            	double tmp;
            	if (t_3 <= 2.0) {
            		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
            	} else if (t_3 <= 3.0001) {
            		tmp = (t_4 + t_1) + (0.5 * (1.0 / Math.sqrt(t)));
            	} else {
            		tmp = (t_4 + (1.0 - Math.sqrt(z))) + t_2;
            	}
            	return tmp;
            }
            
            [x, y, z, t] = sort([x, y, z, t])
            def code(x, y, z, t):
            	t_1 = math.sqrt((z + 1.0)) - math.sqrt(z)
            	t_2 = math.sqrt((t + 1.0)) - math.sqrt(t)
            	t_3 = (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + t_1) + t_2
            	t_4 = (2.0 - math.sqrt(x)) - math.sqrt(y)
            	tmp = 0
            	if t_3 <= 2.0:
            		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
            	elif t_3 <= 3.0001:
            		tmp = (t_4 + t_1) + (0.5 * (1.0 / math.sqrt(t)))
            	else:
            		tmp = (t_4 + (1.0 - math.sqrt(z))) + t_2
            	return tmp
            
            x, y, z, t = sort([x, y, z, t])
            function code(x, y, z, t)
            	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
            	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
            	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
            	t_4 = Float64(Float64(2.0 - sqrt(x)) - sqrt(y))
            	tmp = 0.0
            	if (t_3 <= 2.0)
            		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
            	elseif (t_3 <= 3.0001)
            		tmp = Float64(Float64(t_4 + t_1) + Float64(0.5 * Float64(1.0 / sqrt(t))));
            	else
            		tmp = Float64(Float64(t_4 + Float64(1.0 - sqrt(z))) + t_2);
            	end
            	return tmp
            end
            
            x, y, z, t = num2cell(sort([x, y, z, t])){:}
            function tmp_2 = code(x, y, z, t)
            	t_1 = sqrt((z + 1.0)) - sqrt(z);
            	t_2 = sqrt((t + 1.0)) - sqrt(t);
            	t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
            	t_4 = (2.0 - sqrt(x)) - sqrt(y);
            	tmp = 0.0;
            	if (t_3 <= 2.0)
            		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
            	elseif (t_3 <= 3.0001)
            		tmp = (t_4 + t_1) + (0.5 * (1.0 / sqrt(t)));
            	else
            		tmp = (t_4 + (1.0 - sqrt(z))) + t_2;
            	end
            	tmp_2 = tmp;
            end
            
            NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
            code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, Block[{t$95$4 = N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$3, 2.0], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$3, 3.0001], N[(N[(t$95$4 + t$95$1), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$4 + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]]
            
            \begin{array}{l}
            [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
            \\
            \begin{array}{l}
            t_1 := \sqrt{z + 1} - \sqrt{z}\\
            t_2 := \sqrt{t + 1} - \sqrt{t}\\
            t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
            t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\
            \mathbf{if}\;t\_3 \leq 2:\\
            \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
            
            \mathbf{elif}\;t\_3 \leq 3.0001:\\
            \;\;\;\;\left(t\_4 + t\_1\right) + 0.5 \cdot \frac{1}{\sqrt{t}}\\
            
            \mathbf{else}:\\
            \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_2\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 3 regimes
            2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2

              1. Initial program 88.4%

                \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. Step-by-step derivation
                1. lift--.f64N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. lift-+.f64N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                3. lift-sqrt.f64N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                4. lift-sqrt.f64N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                5. +-commutativeN/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                6. flip--N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                7. lower-/.f64N/A

                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. Applied rewrites88.7%

                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. Taylor expanded in t around inf

                \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
              5. Step-by-step derivation
                1. lower--.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
              6. Applied rewrites8.4%

                \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
              7. Taylor expanded in z around inf

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
              8. Step-by-step derivation
                1. lower--.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                2. lower-+.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                3. lift-sqrt.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                4. lift-+.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                5. lift-sqrt.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                6. lift-sqrt.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                7. lift-+.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                8. lift-+.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                9. lift-/.f64N/A

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                10. lift-sqrt.f6489.9

                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
              9. Applied rewrites89.9%

                \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]

              if 2 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 3.00010000000000021

              1. Initial program 96.6%

                \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. Taylor expanded in y around 0

                \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              3. Step-by-step derivation
                1. associate--r+N/A

                  \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. lower--.f64N/A

                  \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                3. lower--.f64N/A

                  \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                4. +-commutativeN/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                5. lower-+.f64N/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                6. +-commutativeN/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                7. lift-sqrt.f64N/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                8. +-commutativeN/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                9. lower-+.f64N/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                10. lift-sqrt.f64N/A

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                11. lift-sqrt.f6496.4

                  \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              4. Applied rewrites96.4%

                \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              5. Taylor expanded in x around 0

                \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              6. Step-by-step derivation
                1. Applied rewrites96.4%

                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. Taylor expanded in t around inf

                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{t}}} \]
                3. Step-by-step derivation
                  1. lower-*.f64N/A

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{t}}} \]
                  2. sqrt-divN/A

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{\sqrt{1}}{\color{blue}{\sqrt{t}}} \]
                  3. metadata-evalN/A

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{1}{\sqrt{\color{blue}{t}}} \]
                  4. lower-/.f64N/A

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \frac{1}{2} \cdot \frac{1}{\color{blue}{\sqrt{t}}} \]
                  5. lift-sqrt.f6497.9

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + 0.5 \cdot \frac{1}{\sqrt{t}} \]
                4. Applied rewrites97.9%

                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \color{blue}{0.5 \cdot \frac{1}{\sqrt{t}}} \]

                if 3.00010000000000021 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

                1. Initial program 99.5%

                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. Taylor expanded in y around 0

                  \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                3. Step-by-step derivation
                  1. associate--r+N/A

                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. lower--.f64N/A

                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  3. lower--.f64N/A

                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  4. +-commutativeN/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  5. lower-+.f64N/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  6. +-commutativeN/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  7. lift-sqrt.f64N/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  8. +-commutativeN/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  9. lower-+.f64N/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  10. lift-sqrt.f64N/A

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  11. lift-sqrt.f6499.5

                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                4. Applied rewrites99.5%

                  \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                5. Taylor expanded in x around 0

                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                6. Step-by-step derivation
                  1. Applied rewrites99.5%

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Taylor expanded in z around 0

                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  3. Step-by-step derivation
                    1. Applied rewrites98.9%

                      \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  4. Recombined 3 regimes into one program.
                  5. Add Preprocessing

                  Alternative 10: 92.3% accurate, 0.4× speedup?

                  \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \sqrt{t + 1} - \sqrt{t}\\ t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\ t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\ \mathbf{if}\;t\_3 \leq 2:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \mathbf{elif}\;t\_3 \leq 2.99999998:\\ \;\;\;\;\left(t\_4 + t\_1\right) + \left(\sqrt{t} - \sqrt{t}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_2\\ \end{array} \end{array} \]
                  NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                  (FPCore (x y z t)
                   :precision binary64
                   (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z)))
                          (t_2 (- (sqrt (+ t 1.0)) (sqrt t)))
                          (t_3
                           (+
                            (+
                             (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
                             t_1)
                            t_2))
                          (t_4 (- (- 2.0 (sqrt x)) (sqrt y))))
                     (if (<= t_3 2.0)
                       (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))
                       (if (<= t_3 2.99999998)
                         (+ (+ t_4 t_1) (- (sqrt t) (sqrt t)))
                         (+ (+ t_4 (- 1.0 (sqrt z))) t_2)))))
                  assert(x < y && y < z && z < t);
                  double code(double x, double y, double z, double t) {
                  	double t_1 = sqrt((z + 1.0)) - sqrt(z);
                  	double t_2 = sqrt((t + 1.0)) - sqrt(t);
                  	double t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
                  	double t_4 = (2.0 - sqrt(x)) - sqrt(y);
                  	double tmp;
                  	if (t_3 <= 2.0) {
                  		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                  	} else if (t_3 <= 2.99999998) {
                  		tmp = (t_4 + t_1) + (sqrt(t) - sqrt(t));
                  	} else {
                  		tmp = (t_4 + (1.0 - sqrt(z))) + t_2;
                  	}
                  	return tmp;
                  }
                  
                  NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                  module fmin_fmax_functions
                      implicit none
                      private
                      public fmax
                      public fmin
                  
                      interface fmax
                          module procedure fmax88
                          module procedure fmax44
                          module procedure fmax84
                          module procedure fmax48
                      end interface
                      interface fmin
                          module procedure fmin88
                          module procedure fmin44
                          module procedure fmin84
                          module procedure fmin48
                      end interface
                  contains
                      real(8) function fmax88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmax44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmax84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmax48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                      end function
                      real(8) function fmin88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmin44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmin84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmin48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                      end function
                  end module
                  
                  real(8) function code(x, y, z, t)
                  use fmin_fmax_functions
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      real(8), intent (in) :: z
                      real(8), intent (in) :: t
                      real(8) :: t_1
                      real(8) :: t_2
                      real(8) :: t_3
                      real(8) :: t_4
                      real(8) :: tmp
                      t_1 = sqrt((z + 1.0d0)) - sqrt(z)
                      t_2 = sqrt((t + 1.0d0)) - sqrt(t)
                      t_3 = (((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + t_1) + t_2
                      t_4 = (2.0d0 - sqrt(x)) - sqrt(y)
                      if (t_3 <= 2.0d0) then
                          tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
                      else if (t_3 <= 2.99999998d0) then
                          tmp = (t_4 + t_1) + (sqrt(t) - sqrt(t))
                      else
                          tmp = (t_4 + (1.0d0 - sqrt(z))) + t_2
                      end if
                      code = tmp
                  end function
                  
                  assert x < y && y < z && z < t;
                  public static double code(double x, double y, double z, double t) {
                  	double t_1 = Math.sqrt((z + 1.0)) - Math.sqrt(z);
                  	double t_2 = Math.sqrt((t + 1.0)) - Math.sqrt(t);
                  	double t_3 = (((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + t_1) + t_2;
                  	double t_4 = (2.0 - Math.sqrt(x)) - Math.sqrt(y);
                  	double tmp;
                  	if (t_3 <= 2.0) {
                  		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
                  	} else if (t_3 <= 2.99999998) {
                  		tmp = (t_4 + t_1) + (Math.sqrt(t) - Math.sqrt(t));
                  	} else {
                  		tmp = (t_4 + (1.0 - Math.sqrt(z))) + t_2;
                  	}
                  	return tmp;
                  }
                  
                  [x, y, z, t] = sort([x, y, z, t])
                  def code(x, y, z, t):
                  	t_1 = math.sqrt((z + 1.0)) - math.sqrt(z)
                  	t_2 = math.sqrt((t + 1.0)) - math.sqrt(t)
                  	t_3 = (((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + t_1) + t_2
                  	t_4 = (2.0 - math.sqrt(x)) - math.sqrt(y)
                  	tmp = 0
                  	if t_3 <= 2.0:
                  		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
                  	elif t_3 <= 2.99999998:
                  		tmp = (t_4 + t_1) + (math.sqrt(t) - math.sqrt(t))
                  	else:
                  		tmp = (t_4 + (1.0 - math.sqrt(z))) + t_2
                  	return tmp
                  
                  x, y, z, t = sort([x, y, z, t])
                  function code(x, y, z, t)
                  	t_1 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
                  	t_2 = Float64(sqrt(Float64(t + 1.0)) - sqrt(t))
                  	t_3 = Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + t_1) + t_2)
                  	t_4 = Float64(Float64(2.0 - sqrt(x)) - sqrt(y))
                  	tmp = 0.0
                  	if (t_3 <= 2.0)
                  		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
                  	elseif (t_3 <= 2.99999998)
                  		tmp = Float64(Float64(t_4 + t_1) + Float64(sqrt(t) - sqrt(t)));
                  	else
                  		tmp = Float64(Float64(t_4 + Float64(1.0 - sqrt(z))) + t_2);
                  	end
                  	return tmp
                  end
                  
                  x, y, z, t = num2cell(sort([x, y, z, t])){:}
                  function tmp_2 = code(x, y, z, t)
                  	t_1 = sqrt((z + 1.0)) - sqrt(z);
                  	t_2 = sqrt((t + 1.0)) - sqrt(t);
                  	t_3 = (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + t_1) + t_2;
                  	t_4 = (2.0 - sqrt(x)) - sqrt(y);
                  	tmp = 0.0;
                  	if (t_3 <= 2.0)
                  		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                  	elseif (t_3 <= 2.99999998)
                  		tmp = (t_4 + t_1) + (sqrt(t) - sqrt(t));
                  	else
                  		tmp = (t_4 + (1.0 - sqrt(z))) + t_2;
                  	end
                  	tmp_2 = tmp;
                  end
                  
                  NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                  code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]}, Block[{t$95$4 = N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$3, 2.0], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$3, 2.99999998], N[(N[(t$95$4 + t$95$1), $MachinePrecision] + N[(N[Sqrt[t], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$4 + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]]]
                  
                  \begin{array}{l}
                  [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                  \\
                  \begin{array}{l}
                  t_1 := \sqrt{z + 1} - \sqrt{z}\\
                  t_2 := \sqrt{t + 1} - \sqrt{t}\\
                  t_3 := \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + t\_1\right) + t\_2\\
                  t_4 := \left(2 - \sqrt{x}\right) - \sqrt{y}\\
                  \mathbf{if}\;t\_3 \leq 2:\\
                  \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
                  
                  \mathbf{elif}\;t\_3 \leq 2.99999998:\\
                  \;\;\;\;\left(t\_4 + t\_1\right) + \left(\sqrt{t} - \sqrt{t}\right)\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;\left(t\_4 + \left(1 - \sqrt{z}\right)\right) + t\_2\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 3 regimes
                  2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2

                    1. Initial program 88.4%

                      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    2. Step-by-step derivation
                      1. lift--.f64N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      2. lift-+.f64N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      3. lift-sqrt.f64N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      4. lift-sqrt.f64N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      5. +-commutativeN/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      6. flip--N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      7. lower-/.f64N/A

                        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    3. Applied rewrites88.7%

                      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    4. Taylor expanded in t around inf

                      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                    5. Step-by-step derivation
                      1. lower--.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                    6. Applied rewrites8.4%

                      \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                    7. Taylor expanded in z around inf

                      \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
                    8. Step-by-step derivation
                      1. lower--.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      2. lower-+.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      3. lift-sqrt.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      4. lift-+.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      5. lift-sqrt.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      6. lift-sqrt.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      7. lift-+.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      8. lift-+.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      9. lift-/.f64N/A

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                      10. lift-sqrt.f6489.9

                        \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                    9. Applied rewrites89.9%

                      \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]

                    if 2 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 2.9999999800000001

                    1. Initial program 91.2%

                      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    2. Taylor expanded in y around 0

                      \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    3. Step-by-step derivation
                      1. associate--r+N/A

                        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      2. lower--.f64N/A

                        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      3. lower--.f64N/A

                        \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      4. +-commutativeN/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      5. lower-+.f64N/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      6. +-commutativeN/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      7. lift-sqrt.f64N/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      8. +-commutativeN/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      9. lower-+.f64N/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      10. lift-sqrt.f64N/A

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      11. lift-sqrt.f6490.5

                        \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    4. Applied rewrites90.5%

                      \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    5. Taylor expanded in x around 0

                      \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                    6. Step-by-step derivation
                      1. Applied rewrites90.5%

                        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                      2. Taylor expanded in t around inf

                        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{\color{blue}{t}} - \sqrt{t}\right) \]
                      3. Step-by-step derivation
                        1. Applied rewrites89.9%

                          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{\color{blue}{t}} - \sqrt{t}\right) \]

                        if 2.9999999800000001 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

                        1. Initial program 98.6%

                          \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                        2. Taylor expanded in y around 0

                          \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                        3. Step-by-step derivation
                          1. associate--r+N/A

                            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          2. lower--.f64N/A

                            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          3. lower--.f64N/A

                            \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          4. +-commutativeN/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          5. lower-+.f64N/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          6. +-commutativeN/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          7. lift-sqrt.f64N/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          8. +-commutativeN/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          9. lower-+.f64N/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          10. lift-sqrt.f64N/A

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          11. lift-sqrt.f6498.6

                            \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                        4. Applied rewrites98.6%

                          \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                        5. Taylor expanded in x around 0

                          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                        6. Step-by-step derivation
                          1. Applied rewrites98.6%

                            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          2. Taylor expanded in z around 0

                            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          3. Step-by-step derivation
                            1. Applied rewrites98.4%

                              \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                          4. Recombined 3 regimes into one program.
                          5. Add Preprocessing

                          Alternative 11: 89.8% accurate, 1.4× speedup?

                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;z \leq 0.31:\\ \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \end{array} \end{array} \]
                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                          (FPCore (x y z t)
                           :precision binary64
                           (if (<= z 0.31)
                             (+
                              (+ (- (- 2.0 (sqrt x)) (sqrt y)) (- 1.0 (sqrt z)))
                              (- (sqrt (+ t 1.0)) (sqrt t)))
                             (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))))
                          assert(x < y && y < z && z < t);
                          double code(double x, double y, double z, double t) {
                          	double tmp;
                          	if (z <= 0.31) {
                          		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
                          	} else {
                          		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                          	}
                          	return tmp;
                          }
                          
                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                          module fmin_fmax_functions
                              implicit none
                              private
                              public fmax
                              public fmin
                          
                              interface fmax
                                  module procedure fmax88
                                  module procedure fmax44
                                  module procedure fmax84
                                  module procedure fmax48
                              end interface
                              interface fmin
                                  module procedure fmin88
                                  module procedure fmin44
                                  module procedure fmin84
                                  module procedure fmin48
                              end interface
                          contains
                              real(8) function fmax88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmax44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmax84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmax48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                              end function
                              real(8) function fmin88(x, y) result (res)
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(4) function fmin44(x, y) result (res)
                                  real(4), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                              end function
                              real(8) function fmin84(x, y) result(res)
                                  real(8), intent (in) :: x
                                  real(4), intent (in) :: y
                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                              end function
                              real(8) function fmin48(x, y) result(res)
                                  real(4), intent (in) :: x
                                  real(8), intent (in) :: y
                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                              end function
                          end module
                          
                          real(8) function code(x, y, z, t)
                          use fmin_fmax_functions
                              real(8), intent (in) :: x
                              real(8), intent (in) :: y
                              real(8), intent (in) :: z
                              real(8), intent (in) :: t
                              real(8) :: tmp
                              if (z <= 0.31d0) then
                                  tmp = (((2.0d0 - sqrt(x)) - sqrt(y)) + (1.0d0 - sqrt(z))) + (sqrt((t + 1.0d0)) - sqrt(t))
                              else
                                  tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
                              end if
                              code = tmp
                          end function
                          
                          assert x < y && y < z && z < t;
                          public static double code(double x, double y, double z, double t) {
                          	double tmp;
                          	if (z <= 0.31) {
                          		tmp = (((2.0 - Math.sqrt(x)) - Math.sqrt(y)) + (1.0 - Math.sqrt(z))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
                          	} else {
                          		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
                          	}
                          	return tmp;
                          }
                          
                          [x, y, z, t] = sort([x, y, z, t])
                          def code(x, y, z, t):
                          	tmp = 0
                          	if z <= 0.31:
                          		tmp = (((2.0 - math.sqrt(x)) - math.sqrt(y)) + (1.0 - math.sqrt(z))) + (math.sqrt((t + 1.0)) - math.sqrt(t))
                          	else:
                          		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
                          	return tmp
                          
                          x, y, z, t = sort([x, y, z, t])
                          function code(x, y, z, t)
                          	tmp = 0.0
                          	if (z <= 0.31)
                          		tmp = Float64(Float64(Float64(Float64(2.0 - sqrt(x)) - sqrt(y)) + Float64(1.0 - sqrt(z))) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)));
                          	else
                          		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
                          	end
                          	return tmp
                          end
                          
                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                          function tmp_2 = code(x, y, z, t)
                          	tmp = 0.0;
                          	if (z <= 0.31)
                          		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
                          	else
                          		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                          	end
                          	tmp_2 = tmp;
                          end
                          
                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                          code[x_, y_, z_, t_] := If[LessEqual[z, 0.31], N[(N[(N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]]
                          
                          \begin{array}{l}
                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                          \\
                          \begin{array}{l}
                          \mathbf{if}\;z \leq 0.31:\\
                          \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\\
                          
                          \mathbf{else}:\\
                          \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
                          
                          
                          \end{array}
                          \end{array}
                          
                          Derivation
                          1. Split input into 2 regimes
                          2. if z < 0.309999999999999998

                            1. Initial program 98.5%

                              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                            2. Taylor expanded in y around 0

                              \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                            3. Step-by-step derivation
                              1. associate--r+N/A

                                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              2. lower--.f64N/A

                                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              3. lower--.f64N/A

                                \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              4. +-commutativeN/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              5. lower-+.f64N/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              6. +-commutativeN/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              7. lift-sqrt.f64N/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              8. +-commutativeN/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              9. lower-+.f64N/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              10. lift-sqrt.f64N/A

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              11. lift-sqrt.f6498.4

                                \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                            4. Applied rewrites98.4%

                              \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                            5. Taylor expanded in x around 0

                              \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                            6. Step-by-step derivation
                              1. Applied rewrites98.4%

                                \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              2. Taylor expanded in z around 0

                                \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                              3. Step-by-step derivation
                                1. Applied rewrites94.4%

                                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]

                                if 0.309999999999999998 < z

                                1. Initial program 88.2%

                                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                2. Step-by-step derivation
                                  1. lift--.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  2. lift-+.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  3. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  4. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  5. +-commutativeN/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  6. flip--N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  7. lower-/.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                3. Applied rewrites88.5%

                                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                4. Taylor expanded in t around inf

                                  \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                5. Step-by-step derivation
                                  1. lower--.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                                6. Applied rewrites12.0%

                                  \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                7. Taylor expanded in z around inf

                                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
                                8. Step-by-step derivation
                                  1. lower--.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  2. lower-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  3. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  4. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  5. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  6. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  7. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  8. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  9. lift-/.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  10. lift-sqrt.f6487.6

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                9. Applied rewrites87.6%

                                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
                              4. Recombined 2 regimes into one program.
                              5. Add Preprocessing

                              Alternative 12: 70.9% accurate, 0.6× speedup?

                              \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \leq 3.2:\\ \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right)\\ \end{array} \end{array} \]
                              NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                              (FPCore (x y z t)
                               :precision binary64
                               (if (<=
                                    (+
                                     (+
                                      (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y)))
                                      (- (sqrt (+ z 1.0)) (sqrt z)))
                                     (- (sqrt (+ t 1.0)) (sqrt t)))
                                    3.2)
                                 (- (+ (sqrt (+ 1.0 x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))) (sqrt x))
                                 (+ (+ (- (- 2.0 (sqrt x)) (sqrt y)) (- 1.0 (sqrt z))) (- 1.0 (sqrt t)))))
                              assert(x < y && y < z && z < t);
                              double code(double x, double y, double z, double t) {
                              	double tmp;
                              	if (((((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t))) <= 3.2) {
                              		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                              	} else {
                              		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (1.0 - sqrt(t));
                              	}
                              	return tmp;
                              }
                              
                              NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                              module fmin_fmax_functions
                                  implicit none
                                  private
                                  public fmax
                                  public fmin
                              
                                  interface fmax
                                      module procedure fmax88
                                      module procedure fmax44
                                      module procedure fmax84
                                      module procedure fmax48
                                  end interface
                                  interface fmin
                                      module procedure fmin88
                                      module procedure fmin44
                                      module procedure fmin84
                                      module procedure fmin48
                                  end interface
                              contains
                                  real(8) function fmax88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmax44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmax84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmax48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmin44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmin48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                  end function
                              end module
                              
                              real(8) function code(x, y, z, t)
                              use fmin_fmax_functions
                                  real(8), intent (in) :: x
                                  real(8), intent (in) :: y
                                  real(8), intent (in) :: z
                                  real(8), intent (in) :: t
                                  real(8) :: tmp
                                  if (((((sqrt((x + 1.0d0)) - sqrt(x)) + (sqrt((y + 1.0d0)) - sqrt(y))) + (sqrt((z + 1.0d0)) - sqrt(z))) + (sqrt((t + 1.0d0)) - sqrt(t))) <= 3.2d0) then
                                      tmp = (sqrt((1.0d0 + x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y))))) - sqrt(x)
                                  else
                                      tmp = (((2.0d0 - sqrt(x)) - sqrt(y)) + (1.0d0 - sqrt(z))) + (1.0d0 - sqrt(t))
                                  end if
                                  code = tmp
                              end function
                              
                              assert x < y && y < z && z < t;
                              public static double code(double x, double y, double z, double t) {
                              	double tmp;
                              	if (((((Math.sqrt((x + 1.0)) - Math.sqrt(x)) + (Math.sqrt((y + 1.0)) - Math.sqrt(y))) + (Math.sqrt((z + 1.0)) - Math.sqrt(z))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t))) <= 3.2) {
                              		tmp = (Math.sqrt((1.0 + x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y))))) - Math.sqrt(x);
                              	} else {
                              		tmp = (((2.0 - Math.sqrt(x)) - Math.sqrt(y)) + (1.0 - Math.sqrt(z))) + (1.0 - Math.sqrt(t));
                              	}
                              	return tmp;
                              }
                              
                              [x, y, z, t] = sort([x, y, z, t])
                              def code(x, y, z, t):
                              	tmp = 0
                              	if ((((math.sqrt((x + 1.0)) - math.sqrt(x)) + (math.sqrt((y + 1.0)) - math.sqrt(y))) + (math.sqrt((z + 1.0)) - math.sqrt(z))) + (math.sqrt((t + 1.0)) - math.sqrt(t))) <= 3.2:
                              		tmp = (math.sqrt((1.0 + x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y))))) - math.sqrt(x)
                              	else:
                              		tmp = (((2.0 - math.sqrt(x)) - math.sqrt(y)) + (1.0 - math.sqrt(z))) + (1.0 - math.sqrt(t))
                              	return tmp
                              
                              x, y, z, t = sort([x, y, z, t])
                              function code(x, y, z, t)
                              	tmp = 0.0
                              	if (Float64(Float64(Float64(Float64(sqrt(Float64(x + 1.0)) - sqrt(x)) + Float64(sqrt(Float64(y + 1.0)) - sqrt(y))) + Float64(sqrt(Float64(z + 1.0)) - sqrt(z))) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t))) <= 3.2)
                              		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))) - sqrt(x));
                              	else
                              		tmp = Float64(Float64(Float64(Float64(2.0 - sqrt(x)) - sqrt(y)) + Float64(1.0 - sqrt(z))) + Float64(1.0 - sqrt(t)));
                              	end
                              	return tmp
                              end
                              
                              x, y, z, t = num2cell(sort([x, y, z, t])){:}
                              function tmp_2 = code(x, y, z, t)
                              	tmp = 0.0;
                              	if (((((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t))) <= 3.2)
                              		tmp = (sqrt((1.0 + x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y))))) - sqrt(x);
                              	else
                              		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (1.0 - sqrt(t));
                              	end
                              	tmp_2 = tmp;
                              end
                              
                              NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                              code[x_, y_, z_, t_] := If[LessEqual[N[(N[(N[(N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 3.2], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                              
                              \begin{array}{l}
                              [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                              \\
                              \begin{array}{l}
                              \mathbf{if}\;\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \leq 3.2:\\
                              \;\;\;\;\left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x}\\
                              
                              \mathbf{else}:\\
                              \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right)\\
                              
                              
                              \end{array}
                              \end{array}
                              
                              Derivation
                              1. Split input into 2 regimes
                              2. if (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t))) < 3.2000000000000002

                                1. Initial program 90.9%

                                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                2. Step-by-step derivation
                                  1. lift--.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  2. lift-+.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  3. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  4. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  5. +-commutativeN/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  6. flip--N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  7. lower-/.f64N/A

                                    \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                3. Applied rewrites91.1%

                                  \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                4. Taylor expanded in t around inf

                                  \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                5. Step-by-step derivation
                                  1. lower--.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                                6. Applied rewrites34.6%

                                  \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                7. Taylor expanded in z around inf

                                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]
                                8. Step-by-step derivation
                                  1. lower--.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  2. lower-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  3. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  4. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  5. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  6. lift-sqrt.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  7. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  8. lift-+.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  9. lift-/.f64N/A

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                  10. lift-sqrt.f6469.6

                                    \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \sqrt{x} \]
                                9. Applied rewrites69.6%

                                  \[\leadsto \left(\sqrt{1 + x} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) - \color{blue}{\sqrt{x}} \]

                                if 3.2000000000000002 < (+.f64 (+.f64 (+.f64 (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))) (-.f64 (sqrt.f64 (+.f64 z #s(literal 1 binary64))) (sqrt.f64 z))) (-.f64 (sqrt.f64 (+.f64 t #s(literal 1 binary64))) (sqrt.f64 t)))

                                1. Initial program 99.9%

                                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                2. Taylor expanded in y around 0

                                  \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                3. Step-by-step derivation
                                  1. associate--r+N/A

                                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  2. lower--.f64N/A

                                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  3. lower--.f64N/A

                                    \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  4. +-commutativeN/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  5. lower-+.f64N/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  6. +-commutativeN/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  7. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  8. +-commutativeN/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  9. lower-+.f64N/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  10. lift-sqrt.f64N/A

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  11. lift-sqrt.f6499.9

                                    \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                4. Applied rewrites99.9%

                                  \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                5. Taylor expanded in x around 0

                                  \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                6. Step-by-step derivation
                                  1. Applied rewrites99.9%

                                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                  2. Taylor expanded in t around 0

                                    \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\color{blue}{1} - \sqrt{t}\right) \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites91.5%

                                      \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\color{blue}{1} - \sqrt{t}\right) \]
                                    2. Taylor expanded in z around 0

                                      \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right) \]
                                    3. Step-by-step derivation
                                      1. Applied rewrites91.5%

                                        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right) \]
                                    4. Recombined 2 regimes into one program.
                                    5. Add Preprocessing

                                    Alternative 13: 40.0% accurate, 1.6× speedup?

                                    \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;t \leq 1.35:\\ \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\\ \end{array} \end{array} \]
                                    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                    (FPCore (x y z t)
                                     :precision binary64
                                     (if (<= t 1.35)
                                       (+ (+ (- (- 2.0 (sqrt x)) (sqrt y)) (- 1.0 (sqrt z))) (- 1.0 (sqrt t)))
                                       (+ (- (sqrt (+ 1.0 x)) (sqrt x)) (- (sqrt (+ t 1.0)) (sqrt t)))))
                                    assert(x < y && y < z && z < t);
                                    double code(double x, double y, double z, double t) {
                                    	double tmp;
                                    	if (t <= 1.35) {
                                    		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (1.0 - sqrt(t));
                                    	} else {
                                    		tmp = (sqrt((1.0 + x)) - sqrt(x)) + (sqrt((t + 1.0)) - sqrt(t));
                                    	}
                                    	return tmp;
                                    }
                                    
                                    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                    module fmin_fmax_functions
                                        implicit none
                                        private
                                        public fmax
                                        public fmin
                                    
                                        interface fmax
                                            module procedure fmax88
                                            module procedure fmax44
                                            module procedure fmax84
                                            module procedure fmax48
                                        end interface
                                        interface fmin
                                            module procedure fmin88
                                            module procedure fmin44
                                            module procedure fmin84
                                            module procedure fmin48
                                        end interface
                                    contains
                                        real(8) function fmax88(x, y) result (res)
                                            real(8), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                        end function
                                        real(4) function fmax44(x, y) result (res)
                                            real(4), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                        end function
                                        real(8) function fmax84(x, y) result(res)
                                            real(8), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                        end function
                                        real(8) function fmax48(x, y) result(res)
                                            real(4), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                        end function
                                        real(8) function fmin88(x, y) result (res)
                                            real(8), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                        end function
                                        real(4) function fmin44(x, y) result (res)
                                            real(4), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                        end function
                                        real(8) function fmin84(x, y) result(res)
                                            real(8), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                        end function
                                        real(8) function fmin48(x, y) result(res)
                                            real(4), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                        end function
                                    end module
                                    
                                    real(8) function code(x, y, z, t)
                                    use fmin_fmax_functions
                                        real(8), intent (in) :: x
                                        real(8), intent (in) :: y
                                        real(8), intent (in) :: z
                                        real(8), intent (in) :: t
                                        real(8) :: tmp
                                        if (t <= 1.35d0) then
                                            tmp = (((2.0d0 - sqrt(x)) - sqrt(y)) + (1.0d0 - sqrt(z))) + (1.0d0 - sqrt(t))
                                        else
                                            tmp = (sqrt((1.0d0 + x)) - sqrt(x)) + (sqrt((t + 1.0d0)) - sqrt(t))
                                        end if
                                        code = tmp
                                    end function
                                    
                                    assert x < y && y < z && z < t;
                                    public static double code(double x, double y, double z, double t) {
                                    	double tmp;
                                    	if (t <= 1.35) {
                                    		tmp = (((2.0 - Math.sqrt(x)) - Math.sqrt(y)) + (1.0 - Math.sqrt(z))) + (1.0 - Math.sqrt(t));
                                    	} else {
                                    		tmp = (Math.sqrt((1.0 + x)) - Math.sqrt(x)) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
                                    	}
                                    	return tmp;
                                    }
                                    
                                    [x, y, z, t] = sort([x, y, z, t])
                                    def code(x, y, z, t):
                                    	tmp = 0
                                    	if t <= 1.35:
                                    		tmp = (((2.0 - math.sqrt(x)) - math.sqrt(y)) + (1.0 - math.sqrt(z))) + (1.0 - math.sqrt(t))
                                    	else:
                                    		tmp = (math.sqrt((1.0 + x)) - math.sqrt(x)) + (math.sqrt((t + 1.0)) - math.sqrt(t))
                                    	return tmp
                                    
                                    x, y, z, t = sort([x, y, z, t])
                                    function code(x, y, z, t)
                                    	tmp = 0.0
                                    	if (t <= 1.35)
                                    		tmp = Float64(Float64(Float64(Float64(2.0 - sqrt(x)) - sqrt(y)) + Float64(1.0 - sqrt(z))) + Float64(1.0 - sqrt(t)));
                                    	else
                                    		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) - sqrt(x)) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)));
                                    	end
                                    	return tmp
                                    end
                                    
                                    x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                    function tmp_2 = code(x, y, z, t)
                                    	tmp = 0.0;
                                    	if (t <= 1.35)
                                    		tmp = (((2.0 - sqrt(x)) - sqrt(y)) + (1.0 - sqrt(z))) + (1.0 - sqrt(t));
                                    	else
                                    		tmp = (sqrt((1.0 + x)) - sqrt(x)) + (sqrt((t + 1.0)) - sqrt(t));
                                    	end
                                    	tmp_2 = tmp;
                                    end
                                    
                                    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                    code[x_, y_, z_, t_] := If[LessEqual[t, 1.35], N[(N[(N[(N[(2.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                    
                                    \begin{array}{l}
                                    [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                    \\
                                    \begin{array}{l}
                                    \mathbf{if}\;t \leq 1.35:\\
                                    \;\;\;\;\left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(1 - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right)\\
                                    
                                    \mathbf{else}:\\
                                    \;\;\;\;\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\\
                                    
                                    
                                    \end{array}
                                    \end{array}
                                    
                                    Derivation
                                    1. Split input into 2 regimes
                                    2. if t < 1.3500000000000001

                                      1. Initial program 99.9%

                                        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                      2. Taylor expanded in y around 0

                                        \[\leadsto \left(\color{blue}{\left(\left(1 + \sqrt{1 + x}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                      3. Step-by-step derivation
                                        1. associate--r+N/A

                                          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        2. lower--.f64N/A

                                          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        3. lower--.f64N/A

                                          \[\leadsto \left(\left(\left(\left(1 + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        4. +-commutativeN/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        5. lower-+.f64N/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        6. +-commutativeN/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        7. lift-sqrt.f64N/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{x + 1} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        8. +-commutativeN/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        9. lower-+.f64N/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        10. lift-sqrt.f64N/A

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        11. lift-sqrt.f6499.9

                                          \[\leadsto \left(\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                      4. Applied rewrites99.9%

                                        \[\leadsto \left(\color{blue}{\left(\left(\left(\sqrt{1 + x} + 1\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                      5. Taylor expanded in x around 0

                                        \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                      6. Step-by-step derivation
                                        1. Applied rewrites99.9%

                                          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                        2. Taylor expanded in t around 0

                                          \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\color{blue}{1} - \sqrt{t}\right) \]
                                        3. Step-by-step derivation
                                          1. Applied rewrites91.9%

                                            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\color{blue}{1} - \sqrt{t}\right) \]
                                          2. Taylor expanded in z around 0

                                            \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right) \]
                                          3. Step-by-step derivation
                                            1. Applied rewrites91.9%

                                              \[\leadsto \left(\left(\left(2 - \sqrt{x}\right) - \sqrt{y}\right) + \left(\color{blue}{1} - \sqrt{z}\right)\right) + \left(1 - \sqrt{t}\right) \]

                                            if 1.3500000000000001 < t

                                            1. Initial program 90.9%

                                              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. Taylor expanded in z around inf

                                              \[\leadsto \color{blue}{\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. Step-by-step derivation
                                              1. associate--r+N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              2. lower--.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              3. lower--.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              4. lower-+.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              5. +-commutativeN/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              6. lift-sqrt.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              7. +-commutativeN/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              8. lower-+.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              9. +-commutativeN/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              10. lift-sqrt.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              11. lift-+.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              12. lift-sqrt.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              13. lift-sqrt.f6449.4

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. Applied rewrites49.4%

                                              \[\leadsto \color{blue}{\left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. Taylor expanded in y around inf

                                              \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. Step-by-step derivation
                                              1. lower--.f64N/A

                                                \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              2. lift-sqrt.f64N/A

                                                \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              3. lift-+.f64N/A

                                                \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              4. lift-sqrt.f6436.5

                                                \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. Applied rewrites36.5%

                                              \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          4. Recombined 2 regimes into one program.
                                          5. Add Preprocessing

                                          Alternative 14: 35.3% accurate, 2.1× speedup?

                                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \end{array} \]
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          (FPCore (x y z t)
                                           :precision binary64
                                           (+ (- (sqrt (+ 1.0 x)) (sqrt x)) (- (sqrt (+ t 1.0)) (sqrt t))))
                                          assert(x < y && y < z && z < t);
                                          double code(double x, double y, double z, double t) {
                                          	return (sqrt((1.0 + x)) - sqrt(x)) + (sqrt((t + 1.0)) - sqrt(t));
                                          }
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x, y, z, t)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              real(8), intent (in) :: z
                                              real(8), intent (in) :: t
                                              code = (sqrt((1.0d0 + x)) - sqrt(x)) + (sqrt((t + 1.0d0)) - sqrt(t))
                                          end function
                                          
                                          assert x < y && y < z && z < t;
                                          public static double code(double x, double y, double z, double t) {
                                          	return (Math.sqrt((1.0 + x)) - Math.sqrt(x)) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
                                          }
                                          
                                          [x, y, z, t] = sort([x, y, z, t])
                                          def code(x, y, z, t):
                                          	return (math.sqrt((1.0 + x)) - math.sqrt(x)) + (math.sqrt((t + 1.0)) - math.sqrt(t))
                                          
                                          x, y, z, t = sort([x, y, z, t])
                                          function code(x, y, z, t)
                                          	return Float64(Float64(sqrt(Float64(1.0 + x)) - sqrt(x)) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)))
                                          end
                                          
                                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                          function tmp = code(x, y, z, t)
                                          	tmp = (sqrt((1.0 + x)) - sqrt(x)) + (sqrt((t + 1.0)) - sqrt(t));
                                          end
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          code[x_, y_, z_, t_] := N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                          
                                          \begin{array}{l}
                                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                          \\
                                          \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
                                          \end{array}
                                          
                                          Derivation
                                          1. Initial program 91.5%

                                            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          2. Taylor expanded in z around inf

                                            \[\leadsto \color{blue}{\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          3. Step-by-step derivation
                                            1. associate--r+N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. lower--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. lower--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. lower-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            8. lower-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            9. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            10. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            11. lift-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            12. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            13. lift-sqrt.f6447.6

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          4. Applied rewrites47.6%

                                            \[\leadsto \color{blue}{\left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          5. Taylor expanded in y around inf

                                            \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          6. Step-by-step derivation
                                            1. lower--.f64N/A

                                              \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. lift-sqrt.f64N/A

                                              \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. lift-+.f64N/A

                                              \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. lift-sqrt.f6435.3

                                              \[\leadsto \left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          7. Applied rewrites35.3%

                                            \[\leadsto \left(\sqrt{1 + x} - \color{blue}{\sqrt{x}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          8. Add Preprocessing

                                          Alternative 15: 11.4% accurate, 1.8× speedup?

                                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;z \leq 1.6 \cdot 10^{+32}:\\ \;\;\;\;\left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \frac{1}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right)\\ \end{array} \end{array} \]
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          (FPCore (x y z t)
                                           :precision binary64
                                           (if (<= z 1.6e+32)
                                             (- (+ (sqrt (+ 1.0 x)) (sqrt z)) (+ (sqrt x) (sqrt z)))
                                             (+ (* 0.5 (/ 1.0 (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t)))))
                                          assert(x < y && y < z && z < t);
                                          double code(double x, double y, double z, double t) {
                                          	double tmp;
                                          	if (z <= 1.6e+32) {
                                          		tmp = (sqrt((1.0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z));
                                          	} else {
                                          		tmp = (0.5 * (1.0 / sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
                                          	}
                                          	return tmp;
                                          }
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x, y, z, t)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              real(8), intent (in) :: z
                                              real(8), intent (in) :: t
                                              real(8) :: tmp
                                              if (z <= 1.6d+32) then
                                                  tmp = (sqrt((1.0d0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z))
                                              else
                                                  tmp = (0.5d0 * (1.0d0 / sqrt(z))) + (sqrt((t + 1.0d0)) - sqrt(t))
                                              end if
                                              code = tmp
                                          end function
                                          
                                          assert x < y && y < z && z < t;
                                          public static double code(double x, double y, double z, double t) {
                                          	double tmp;
                                          	if (z <= 1.6e+32) {
                                          		tmp = (Math.sqrt((1.0 + x)) + Math.sqrt(z)) - (Math.sqrt(x) + Math.sqrt(z));
                                          	} else {
                                          		tmp = (0.5 * (1.0 / Math.sqrt(z))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
                                          	}
                                          	return tmp;
                                          }
                                          
                                          [x, y, z, t] = sort([x, y, z, t])
                                          def code(x, y, z, t):
                                          	tmp = 0
                                          	if z <= 1.6e+32:
                                          		tmp = (math.sqrt((1.0 + x)) + math.sqrt(z)) - (math.sqrt(x) + math.sqrt(z))
                                          	else:
                                          		tmp = (0.5 * (1.0 / math.sqrt(z))) + (math.sqrt((t + 1.0)) - math.sqrt(t))
                                          	return tmp
                                          
                                          x, y, z, t = sort([x, y, z, t])
                                          function code(x, y, z, t)
                                          	tmp = 0.0
                                          	if (z <= 1.6e+32)
                                          		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + sqrt(z)) - Float64(sqrt(x) + sqrt(z)));
                                          	else
                                          		tmp = Float64(Float64(0.5 * Float64(1.0 / sqrt(z))) + Float64(sqrt(Float64(t + 1.0)) - sqrt(t)));
                                          	end
                                          	return tmp
                                          end
                                          
                                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                          function tmp_2 = code(x, y, z, t)
                                          	tmp = 0.0;
                                          	if (z <= 1.6e+32)
                                          		tmp = (sqrt((1.0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z));
                                          	else
                                          		tmp = (0.5 * (1.0 / sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
                                          	end
                                          	tmp_2 = tmp;
                                          end
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          code[x_, y_, z_, t_] := If[LessEqual[z, 1.6e+32], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[(1.0 / N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                                          
                                          \begin{array}{l}
                                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                          \\
                                          \begin{array}{l}
                                          \mathbf{if}\;z \leq 1.6 \cdot 10^{+32}:\\
                                          \;\;\;\;\left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right)\\
                                          
                                          \mathbf{else}:\\
                                          \;\;\;\;0.5 \cdot \frac{1}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right)\\
                                          
                                          
                                          \end{array}
                                          \end{array}
                                          
                                          Derivation
                                          1. Split input into 2 regimes
                                          2. if z < 1.5999999999999999e32

                                            1. Initial program 95.3%

                                              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. Step-by-step derivation
                                              1. lift--.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              2. lift-+.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              3. lift-sqrt.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              4. lift-sqrt.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              5. +-commutativeN/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              6. flip--N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              7. lower-/.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. Applied rewrites95.3%

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. Taylor expanded in t around inf

                                              \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                            5. Step-by-step derivation
                                              1. lower--.f64N/A

                                                \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                                            6. Applied rewrites80.3%

                                              \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                            7. Taylor expanded in z around inf

                                              \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]
                                            8. Step-by-step derivation
                                              1. lift-sqrt.f6418.5

                                                \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]
                                            9. Applied rewrites18.5%

                                              \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]

                                            if 1.5999999999999999e32 < z

                                            1. Initial program 89.0%

                                              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. Taylor expanded in z around inf

                                              \[\leadsto \color{blue}{\left(\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \frac{1}{2} \cdot \sqrt{\frac{1}{z}}\right)\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. Step-by-step derivation
                                              1. associate--r+N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \frac{1}{2} \cdot \sqrt{\frac{1}{z}}\right)\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              2. lower--.f64N/A

                                                \[\leadsto \left(\left(\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \frac{1}{2} \cdot \sqrt{\frac{1}{z}}\right)\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. Applied rewrites59.7%

                                              \[\leadsto \color{blue}{\left(\left(\left(\mathsf{fma}\left(\frac{1}{\sqrt{z}}, 0.5, \sqrt{y + 1}\right) + \sqrt{1 + x}\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. Taylor expanded in z around 0

                                              \[\leadsto \frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{z}}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. Step-by-step derivation
                                              1. lower-*.f64N/A

                                                \[\leadsto \frac{1}{2} \cdot \sqrt{\frac{1}{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              2. sqrt-divN/A

                                                \[\leadsto \frac{1}{2} \cdot \frac{\sqrt{1}}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              3. metadata-evalN/A

                                                \[\leadsto \frac{1}{2} \cdot \frac{1}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              4. lift-sqrt.f64N/A

                                                \[\leadsto \frac{1}{2} \cdot \frac{1}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                              5. lift-/.f646.8

                                                \[\leadsto 0.5 \cdot \frac{1}{\sqrt{z}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. Applied rewrites6.8%

                                              \[\leadsto 0.5 \cdot \color{blue}{\frac{1}{\sqrt{z}}} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          3. Recombined 2 regimes into one program.
                                          4. Add Preprocessing

                                          Alternative 16: 9.2% accurate, 2.4× speedup?

                                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \end{array} \]
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          (FPCore (x y z t)
                                           :precision binary64
                                           (- (+ (sqrt (+ 1.0 x)) (sqrt z)) (+ (sqrt x) (sqrt z))))
                                          assert(x < y && y < z && z < t);
                                          double code(double x, double y, double z, double t) {
                                          	return (sqrt((1.0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z));
                                          }
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x, y, z, t)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              real(8), intent (in) :: z
                                              real(8), intent (in) :: t
                                              code = (sqrt((1.0d0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z))
                                          end function
                                          
                                          assert x < y && y < z && z < t;
                                          public static double code(double x, double y, double z, double t) {
                                          	return (Math.sqrt((1.0 + x)) + Math.sqrt(z)) - (Math.sqrt(x) + Math.sqrt(z));
                                          }
                                          
                                          [x, y, z, t] = sort([x, y, z, t])
                                          def code(x, y, z, t):
                                          	return (math.sqrt((1.0 + x)) + math.sqrt(z)) - (math.sqrt(x) + math.sqrt(z))
                                          
                                          x, y, z, t = sort([x, y, z, t])
                                          function code(x, y, z, t)
                                          	return Float64(Float64(sqrt(Float64(1.0 + x)) + sqrt(z)) - Float64(sqrt(x) + sqrt(z)))
                                          end
                                          
                                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                          function tmp = code(x, y, z, t)
                                          	tmp = (sqrt((1.0 + x)) + sqrt(z)) - (sqrt(x) + sqrt(z));
                                          end
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          code[x_, y_, z_, t_] := N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                          
                                          \begin{array}{l}
                                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                          \\
                                          \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right)
                                          \end{array}
                                          
                                          Derivation
                                          1. Initial program 91.5%

                                            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          2. Step-by-step derivation
                                            1. lift--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. lift-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. flip--N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. lower-/.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          3. Applied rewrites91.7%

                                            \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          4. Taylor expanded in t around inf

                                            \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                          5. Step-by-step derivation
                                            1. lower--.f64N/A

                                              \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                                          6. Applied rewrites33.7%

                                            \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                          7. Taylor expanded in z around inf

                                            \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]
                                          8. Step-by-step derivation
                                            1. lift-sqrt.f649.2

                                              \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]
                                          9. Applied rewrites9.2%

                                            \[\leadsto \left(\sqrt{1 + x} + \sqrt{z}\right) - \left(\sqrt{x} + \sqrt{z}\right) \]
                                          10. Add Preprocessing

                                          Alternative 17: 6.2% accurate, 2.5× speedup?

                                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \left(\sqrt{y} - \sqrt{y}\right) + 0.5 \cdot \frac{1}{\sqrt{t}} \end{array} \]
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          (FPCore (x y z t)
                                           :precision binary64
                                           (+ (- (sqrt y) (sqrt y)) (* 0.5 (/ 1.0 (sqrt t)))))
                                          assert(x < y && y < z && z < t);
                                          double code(double x, double y, double z, double t) {
                                          	return (sqrt(y) - sqrt(y)) + (0.5 * (1.0 / sqrt(t)));
                                          }
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x, y, z, t)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              real(8), intent (in) :: z
                                              real(8), intent (in) :: t
                                              code = (sqrt(y) - sqrt(y)) + (0.5d0 * (1.0d0 / sqrt(t)))
                                          end function
                                          
                                          assert x < y && y < z && z < t;
                                          public static double code(double x, double y, double z, double t) {
                                          	return (Math.sqrt(y) - Math.sqrt(y)) + (0.5 * (1.0 / Math.sqrt(t)));
                                          }
                                          
                                          [x, y, z, t] = sort([x, y, z, t])
                                          def code(x, y, z, t):
                                          	return (math.sqrt(y) - math.sqrt(y)) + (0.5 * (1.0 / math.sqrt(t)))
                                          
                                          x, y, z, t = sort([x, y, z, t])
                                          function code(x, y, z, t)
                                          	return Float64(Float64(sqrt(y) - sqrt(y)) + Float64(0.5 * Float64(1.0 / sqrt(t))))
                                          end
                                          
                                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                          function tmp = code(x, y, z, t)
                                          	tmp = (sqrt(y) - sqrt(y)) + (0.5 * (1.0 / sqrt(t)));
                                          end
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          code[x_, y_, z_, t_] := N[(N[(N[Sqrt[y], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                          
                                          \begin{array}{l}
                                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                          \\
                                          \left(\sqrt{y} - \sqrt{y}\right) + 0.5 \cdot \frac{1}{\sqrt{t}}
                                          \end{array}
                                          
                                          Derivation
                                          1. Initial program 91.5%

                                            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          2. Taylor expanded in z around inf

                                            \[\leadsto \color{blue}{\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          3. Step-by-step derivation
                                            1. associate--r+N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. lower--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \color{blue}{\sqrt{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. lower--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. lower-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            8. lower-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            9. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            10. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            11. lift-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            12. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            13. lift-sqrt.f6447.6

                                              \[\leadsto \left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          4. Applied rewrites47.6%

                                            \[\leadsto \color{blue}{\left(\left(\left(\sqrt{1 + x} + \sqrt{y + 1}\right) - \sqrt{x}\right) - \sqrt{y}\right)} + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          5. Taylor expanded in y around inf

                                            \[\leadsto \left(\sqrt{y} - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          6. Step-by-step derivation
                                            1. lift-sqrt.f644.2

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          7. Applied rewrites4.2%

                                            \[\leadsto \left(\sqrt{y} - \sqrt{\color{blue}{y}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          8. Taylor expanded in t around inf

                                            \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \color{blue}{\frac{1}{2} \cdot \sqrt{\frac{1}{t}}} \]
                                          9. Step-by-step derivation
                                            1. lower-*.f64N/A

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \frac{1}{2} \cdot \color{blue}{\sqrt{\frac{1}{t}}} \]
                                            2. sqrt-divN/A

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \frac{1}{2} \cdot \frac{\sqrt{1}}{\color{blue}{\sqrt{t}}} \]
                                            3. metadata-evalN/A

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \frac{1}{2} \cdot \frac{1}{\sqrt{\color{blue}{t}}} \]
                                            4. lower-/.f64N/A

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \frac{1}{2} \cdot \frac{1}{\color{blue}{\sqrt{t}}} \]
                                            5. lift-sqrt.f646.2

                                              \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + 0.5 \cdot \frac{1}{\sqrt{t}} \]
                                          10. Applied rewrites6.2%

                                            \[\leadsto \left(\sqrt{y} - \sqrt{y}\right) + \color{blue}{0.5 \cdot \frac{1}{\sqrt{t}}} \]
                                          11. Add Preprocessing

                                          Alternative 18: 3.1% accurate, 6.3× speedup?

                                          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \sqrt{x} - \sqrt{x} \end{array} \]
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          (FPCore (x y z t) :precision binary64 (- (sqrt x) (sqrt x)))
                                          assert(x < y && y < z && z < t);
                                          double code(double x, double y, double z, double t) {
                                          	return sqrt(x) - sqrt(x);
                                          }
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x, y, z, t)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              real(8), intent (in) :: z
                                              real(8), intent (in) :: t
                                              code = sqrt(x) - sqrt(x)
                                          end function
                                          
                                          assert x < y && y < z && z < t;
                                          public static double code(double x, double y, double z, double t) {
                                          	return Math.sqrt(x) - Math.sqrt(x);
                                          }
                                          
                                          [x, y, z, t] = sort([x, y, z, t])
                                          def code(x, y, z, t):
                                          	return math.sqrt(x) - math.sqrt(x)
                                          
                                          x, y, z, t = sort([x, y, z, t])
                                          function code(x, y, z, t)
                                          	return Float64(sqrt(x) - sqrt(x))
                                          end
                                          
                                          x, y, z, t = num2cell(sort([x, y, z, t])){:}
                                          function tmp = code(x, y, z, t)
                                          	tmp = sqrt(x) - sqrt(x);
                                          end
                                          
                                          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                                          code[x_, y_, z_, t_] := N[(N[Sqrt[x], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
                                          
                                          \begin{array}{l}
                                          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                                          \\
                                          \sqrt{x} - \sqrt{x}
                                          \end{array}
                                          
                                          Derivation
                                          1. Initial program 91.5%

                                            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          2. Step-by-step derivation
                                            1. lift--.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            2. lift-+.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            3. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\color{blue}{\sqrt{y + 1}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            4. lift-sqrt.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \color{blue}{\sqrt{y}}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            5. +-commutativeN/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            6. flip--N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                            7. lower-/.f64N/A

                                              \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          3. Applied rewrites91.7%

                                            \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                                          4. Taylor expanded in t around inf

                                            \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                          5. Step-by-step derivation
                                            1. lower--.f64N/A

                                              \[\leadsto \left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \color{blue}{\left(\sqrt{x} + \sqrt{z}\right)} \]
                                          6. Applied rewrites33.7%

                                            \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + z} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \left(\sqrt{x} + \sqrt{z}\right)} \]
                                          7. Taylor expanded in x around inf

                                            \[\leadsto \sqrt{x} - \left(\color{blue}{\sqrt{x}} + \sqrt{z}\right) \]
                                          8. Step-by-step derivation
                                            1. lift-sqrt.f641.5

                                              \[\leadsto \sqrt{x} - \left(\sqrt{x} + \sqrt{z}\right) \]
                                          9. Applied rewrites1.5%

                                            \[\leadsto \sqrt{x} - \left(\color{blue}{\sqrt{x}} + \sqrt{z}\right) \]
                                          10. Taylor expanded in x around inf

                                            \[\leadsto \sqrt{x} - \sqrt{x} \]
                                          11. Step-by-step derivation
                                            1. lift-sqrt.f643.1

                                              \[\leadsto \sqrt{x} - \sqrt{x} \]
                                          12. Applied rewrites3.1%

                                            \[\leadsto \sqrt{x} - \sqrt{x} \]
                                          13. Add Preprocessing

                                          Reproduce

                                          ?
                                          herbie shell --seed 2025112 
                                          (FPCore (x y z t)
                                            :name "Main:z from "
                                            :precision binary64
                                            (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))