Main:z from

Percentage Accurate: 91.5% → 99.5%
Time: 34.0s
Alternatives: 19
Speedup: 1.3×

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));
}
real(8) function code(x, y, z, t)
    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}

Sampling outcomes in binary64 precision:

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 19 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));
}
real(8) function code(x, y, z, t)
    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: 99.5% accurate, 0.7× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y} + \sqrt{1 + y}\\ t_2 := \sqrt{1 + t}\\ t_3 := \sqrt{x} + \sqrt{1 + x}\\ \mathbf{if}\;z \leq 360000:\\ \;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + \mathsf{fma}\left(0.5, y, \frac{1}{t\_2 + \sqrt{t}}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(t\_1 + t\_3\right) \cdot \frac{1}{t\_1 \cdot t\_3} + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(t\_2 - \sqrt{t}\right)\right)\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (+ (sqrt y) (sqrt (+ 1.0 y))))
        (t_2 (sqrt (+ 1.0 t)))
        (t_3 (+ (sqrt x) (sqrt (+ 1.0 x)))))
   (if (<= z 360000.0)
     (-
      (+ (+ (sqrt (+ z 1.0)) 2.0) (fma 0.5 y (/ 1.0 (+ t_2 (sqrt t)))))
      (+ (sqrt x) (+ (sqrt y) (sqrt z))))
     (+
      (* (+ t_1 t_3) (/ 1.0 (* t_1 t_3)))
      (+ (* 0.5 (sqrt (/ 1.0 z))) (- t_2 (sqrt t)))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt(y) + sqrt((1.0 + y));
	double t_2 = sqrt((1.0 + t));
	double t_3 = sqrt(x) + sqrt((1.0 + x));
	double tmp;
	if (z <= 360000.0) {
		tmp = ((sqrt((z + 1.0)) + 2.0) + fma(0.5, y, (1.0 / (t_2 + sqrt(t))))) - (sqrt(x) + (sqrt(y) + sqrt(z)));
	} else {
		tmp = ((t_1 + t_3) * (1.0 / (t_1 * t_3))) + ((0.5 * sqrt((1.0 / z))) + (t_2 - sqrt(t)));
	}
	return tmp;
}
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(sqrt(y) + sqrt(Float64(1.0 + y)))
	t_2 = sqrt(Float64(1.0 + t))
	t_3 = Float64(sqrt(x) + sqrt(Float64(1.0 + x)))
	tmp = 0.0
	if (z <= 360000.0)
		tmp = Float64(Float64(Float64(sqrt(Float64(z + 1.0)) + 2.0) + fma(0.5, y, Float64(1.0 / Float64(t_2 + sqrt(t))))) - Float64(sqrt(x) + Float64(sqrt(y) + sqrt(z))));
	else
		tmp = Float64(Float64(Float64(t_1 + t_3) * Float64(1.0 / Float64(t_1 * t_3))) + Float64(Float64(0.5 * sqrt(Float64(1.0 / z))) + Float64(t_2 - sqrt(t))));
	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[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$3 = N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[z, 360000.0], N[(N[(N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] + 2.0), $MachinePrecision] + N[(0.5 * y + N[(1.0 / N[(t$95$2 + N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(t$95$1 + t$95$3), $MachinePrecision] * N[(1.0 / N[(t$95$1 * t$95$3), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(t$95$2 - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := \sqrt{y} + \sqrt{1 + y}\\
t_2 := \sqrt{1 + t}\\
t_3 := \sqrt{x} + \sqrt{1 + x}\\
\mathbf{if}\;z \leq 360000:\\
\;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + \mathsf{fma}\left(0.5, y, \frac{1}{t\_2 + \sqrt{t}}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(t\_1 + t\_3\right) \cdot \frac{1}{t\_1 \cdot t\_3} + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(t\_2 - \sqrt{t}\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < 3.6e5

    1. Initial program 97.0%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. sub-neg97.0%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. sub-neg97.0%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. +-commutative97.0%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      5. +-commutative97.0%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      6. +-commutative97.0%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
    3. Simplified97.0%

      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 50.7%

      \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
    6. Step-by-step derivation
      1. flip--50.7%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\frac{\sqrt{1 + t} \cdot \sqrt{1 + t} - \sqrt{t} \cdot \sqrt{t}}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
      2. div-inv50.7%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\left(\sqrt{1 + t} \cdot \sqrt{1 + t} - \sqrt{t} \cdot \sqrt{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
      3. add-sqr-sqrt36.3%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\color{blue}{\left(1 + t\right)} - \sqrt{t} \cdot \sqrt{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}\right) \]
      4. add-sqr-sqrt50.7%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\left(1 + t\right) - \color{blue}{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}\right) \]
    7. Applied egg-rr50.7%

      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\left(\left(1 + t\right) - t\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
    8. Step-by-step derivation
      1. associate-*r/50.7%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\frac{\left(\left(1 + t\right) - t\right) \cdot 1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
      2. *-rgt-identity50.7%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{\left(1 + t\right) - t}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
      3. associate--l+51.3%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{1 + \left(t - t\right)}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
      4. +-inverses51.3%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
      5. metadata-eval51.3%

        \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{1}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
    9. Simplified51.3%

      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\frac{1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
    10. Taylor expanded in y around 0 32.4%

      \[\leadsto \color{blue}{\left(2 + \left(\sqrt{1 + z} + \left(0.5 \cdot y + \frac{1}{\sqrt{t} + \sqrt{1 + t}}\right)\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
    11. Step-by-step derivation
      1. associate-+r+32.5%

        \[\leadsto \color{blue}{\left(\left(2 + \sqrt{1 + z}\right) + \left(0.5 \cdot y + \frac{1}{\sqrt{t} + \sqrt{1 + t}}\right)\right)} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
      2. +-commutative32.5%

        \[\leadsto \left(\color{blue}{\left(\sqrt{1 + z} + 2\right)} + \left(0.5 \cdot y + \frac{1}{\sqrt{t} + \sqrt{1 + t}}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
      3. fma-define32.5%

        \[\leadsto \left(\left(\sqrt{1 + z} + 2\right) + \color{blue}{\mathsf{fma}\left(0.5, y, \frac{1}{\sqrt{t} + \sqrt{1 + t}}\right)}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
      4. +-commutative32.5%

        \[\leadsto \left(\left(\sqrt{1 + z} + 2\right) + \mathsf{fma}\left(0.5, y, \frac{1}{\color{blue}{\sqrt{1 + t} + \sqrt{t}}}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
    12. Simplified32.5%

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

    if 3.6e5 < z

    1. Initial program 87.7%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+87.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. sub-neg87.7%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. sub-neg87.7%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. +-commutative87.7%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      5. +-commutative87.7%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      6. +-commutative87.7%

        \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
    3. Simplified87.7%

      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. flip--87.9%

        \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      2. flip--87.9%

        \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      3. frac-add87.8%

        \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
    6. Applied egg-rr88.4%

      \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
    7. Step-by-step derivation
      1. Simplified91.5%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      2. Step-by-step derivation
        1. expm1-log1p-u88.1%

          \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)\right)\right)}}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        2. expm1-undefine88.1%

          \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)\right)} - 1}}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        3. hypot-undefine88.1%

          \[\leadsto \frac{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \color{blue}{\sqrt{1 \cdot 1 + \sqrt{x} \cdot \sqrt{x}}}\right)\right)} - 1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        4. metadata-eval88.1%

          \[\leadsto \frac{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{\color{blue}{1} + \sqrt{x} \cdot \sqrt{x}}\right)\right)} - 1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        5. add-sqr-sqrt88.1%

          \[\leadsto \frac{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{1 + \color{blue}{x}}\right)\right)} - 1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        6. +-commutative88.1%

          \[\leadsto \frac{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{\color{blue}{x + 1}}\right)\right)} - 1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      3. Applied egg-rr88.1%

        \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{x + 1}\right)\right)} - 1}}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      4. Step-by-step derivation
        1. expm1-define88.1%

          \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{x + 1}\right)\right)\right)}}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        2. +-commutative88.1%

          \[\leadsto \frac{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(\color{blue}{\left(1 - x\right) + x}, \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{x + 1}\right)\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        3. associate-+l-89.2%

          \[\leadsto \frac{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(\color{blue}{1 - \left(x - x\right)}, \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \sqrt{x + 1}\right)\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        4. +-commutative89.2%

          \[\leadsto \frac{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(1 - \left(x - x\right), \color{blue}{\sqrt{y} + \sqrt{1 + y}}, \sqrt{x} + \sqrt{x + 1}\right)\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        5. +-commutative89.2%

          \[\leadsto \frac{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(1 - \left(x - x\right), \sqrt{y} + \sqrt{1 + y}, \sqrt{x} + \sqrt{\color{blue}{1 + x}}\right)\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      5. Simplified89.2%

        \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(1 - \left(x - x\right), \sqrt{y} + \sqrt{1 + y}, \sqrt{x} + \sqrt{1 + x}\right)\right)\right)}}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      6. Step-by-step derivation
        1. div-inv89.2%

          \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(1 - \left(x - x\right), \sqrt{y} + \sqrt{1 + y}, \sqrt{x} + \sqrt{1 + x}\right)\right)\right) \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        2. expm1-log1p-u92.7%

          \[\leadsto \color{blue}{\mathsf{fma}\left(1 - \left(x - x\right), \sqrt{y} + \sqrt{1 + y}, \sqrt{x} + \sqrt{1 + x}\right)} \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        3. fma-undefine92.7%

          \[\leadsto \color{blue}{\left(\left(1 - \left(x - x\right)\right) \cdot \left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right)} \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        4. +-inverses92.7%

          \[\leadsto \left(\left(1 - \color{blue}{0}\right) \cdot \left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        5. metadata-eval92.7%

          \[\leadsto \left(\color{blue}{1} \cdot \left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        6. *-un-lft-identity92.7%

          \[\leadsto \left(\color{blue}{\left(\sqrt{y} + \sqrt{1 + y}\right)} + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        7. +-commutative92.7%

          \[\leadsto \left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\color{blue}{\left(\sqrt{y} + \sqrt{1 + y}\right)} \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        8. hypot-undefine92.7%

          \[\leadsto \left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \color{blue}{\sqrt{1 \cdot 1 + \sqrt{x} \cdot \sqrt{x}}}\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        9. metadata-eval92.7%

          \[\leadsto \left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \sqrt{\color{blue}{1} + \sqrt{x} \cdot \sqrt{x}}\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        10. add-sqr-sqrt92.7%

          \[\leadsto \left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \sqrt{1 + \color{blue}{x}}\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      7. Applied egg-rr92.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \sqrt{1 + x}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      8. Taylor expanded in z around inf 95.6%

        \[\leadsto \left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \sqrt{1 + x}\right)} + \left(\color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
    8. Recombined 2 regimes into one program.
    9. Final simplification62.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 360000:\\ \;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + \mathsf{fma}\left(0.5, y, \frac{1}{\sqrt{1 + t} + \sqrt{t}}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\sqrt{y} + \sqrt{1 + y}\right) + \left(\sqrt{x} + \sqrt{1 + x}\right)\right) \cdot \frac{1}{\left(\sqrt{y} + \sqrt{1 + y}\right) \cdot \left(\sqrt{x} + \sqrt{1 + x}\right)} + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\\ \end{array} \]
    10. Add Preprocessing

    Alternative 2: 98.9% accurate, 0.5× speedup?

    \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + x}\\ t_2 := \sqrt{1 + y} - \sqrt{y}\\ t_3 := \sqrt{1 + t} - \sqrt{t}\\ t_4 := \sqrt{z + 1}\\ t_5 := t\_4 - \sqrt{z}\\ \mathbf{if}\;t\_3 + \left(\left(\left(t\_1 - \sqrt{x}\right) + t\_2\right) + t\_5\right) \leq 1.0001:\\ \;\;\;\;\left(0.5 \cdot \sqrt{\frac{1}{y}} + \frac{1}{\sqrt{x} + t\_1}\right) + \left(t\_3 + t\_5\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + t\_2\right) + \left(t\_3 + \frac{1}{t\_4 + \sqrt{z}}\right)\\ \end{array} \end{array} \]
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    (FPCore (x y z t)
     :precision binary64
     (let* ((t_1 (sqrt (+ 1.0 x)))
            (t_2 (- (sqrt (+ 1.0 y)) (sqrt y)))
            (t_3 (- (sqrt (+ 1.0 t)) (sqrt t)))
            (t_4 (sqrt (+ z 1.0)))
            (t_5 (- t_4 (sqrt z))))
       (if (<= (+ t_3 (+ (+ (- t_1 (sqrt x)) t_2) t_5)) 1.0001)
         (+ (+ (* 0.5 (sqrt (/ 1.0 y))) (/ 1.0 (+ (sqrt x) t_1))) (+ t_3 t_5))
         (+ (+ (- 1.0 (sqrt x)) t_2) (+ t_3 (/ 1.0 (+ t_4 (sqrt z))))))))
    assert(x < y && y < z && z < t);
    double code(double x, double y, double z, double t) {
    	double t_1 = sqrt((1.0 + x));
    	double t_2 = sqrt((1.0 + y)) - sqrt(y);
    	double t_3 = sqrt((1.0 + t)) - sqrt(t);
    	double t_4 = sqrt((z + 1.0));
    	double t_5 = t_4 - sqrt(z);
    	double tmp;
    	if ((t_3 + (((t_1 - sqrt(x)) + t_2) + t_5)) <= 1.0001) {
    		tmp = ((0.5 * sqrt((1.0 / y))) + (1.0 / (sqrt(x) + t_1))) + (t_3 + t_5);
    	} else {
    		tmp = ((1.0 - sqrt(x)) + t_2) + (t_3 + (1.0 / (t_4 + sqrt(z))));
    	}
    	return tmp;
    }
    
    NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
    real(8) function code(x, y, z, t)
        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) :: t_5
        real(8) :: tmp
        t_1 = sqrt((1.0d0 + x))
        t_2 = sqrt((1.0d0 + y)) - sqrt(y)
        t_3 = sqrt((1.0d0 + t)) - sqrt(t)
        t_4 = sqrt((z + 1.0d0))
        t_5 = t_4 - sqrt(z)
        if ((t_3 + (((t_1 - sqrt(x)) + t_2) + t_5)) <= 1.0001d0) then
            tmp = ((0.5d0 * sqrt((1.0d0 / y))) + (1.0d0 / (sqrt(x) + t_1))) + (t_3 + t_5)
        else
            tmp = ((1.0d0 - sqrt(x)) + t_2) + (t_3 + (1.0d0 / (t_4 + sqrt(z))))
        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((1.0 + x));
    	double t_2 = Math.sqrt((1.0 + y)) - Math.sqrt(y);
    	double t_3 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
    	double t_4 = Math.sqrt((z + 1.0));
    	double t_5 = t_4 - Math.sqrt(z);
    	double tmp;
    	if ((t_3 + (((t_1 - Math.sqrt(x)) + t_2) + t_5)) <= 1.0001) {
    		tmp = ((0.5 * Math.sqrt((1.0 / y))) + (1.0 / (Math.sqrt(x) + t_1))) + (t_3 + t_5);
    	} else {
    		tmp = ((1.0 - Math.sqrt(x)) + t_2) + (t_3 + (1.0 / (t_4 + Math.sqrt(z))));
    	}
    	return tmp;
    }
    
    [x, y, z, t] = sort([x, y, z, t])
    def code(x, y, z, t):
    	t_1 = math.sqrt((1.0 + x))
    	t_2 = math.sqrt((1.0 + y)) - math.sqrt(y)
    	t_3 = math.sqrt((1.0 + t)) - math.sqrt(t)
    	t_4 = math.sqrt((z + 1.0))
    	t_5 = t_4 - math.sqrt(z)
    	tmp = 0
    	if (t_3 + (((t_1 - math.sqrt(x)) + t_2) + t_5)) <= 1.0001:
    		tmp = ((0.5 * math.sqrt((1.0 / y))) + (1.0 / (math.sqrt(x) + t_1))) + (t_3 + t_5)
    	else:
    		tmp = ((1.0 - math.sqrt(x)) + t_2) + (t_3 + (1.0 / (t_4 + math.sqrt(z))))
    	return tmp
    
    x, y, z, t = sort([x, y, z, t])
    function code(x, y, z, t)
    	t_1 = sqrt(Float64(1.0 + x))
    	t_2 = Float64(sqrt(Float64(1.0 + y)) - sqrt(y))
    	t_3 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
    	t_4 = sqrt(Float64(z + 1.0))
    	t_5 = Float64(t_4 - sqrt(z))
    	tmp = 0.0
    	if (Float64(t_3 + Float64(Float64(Float64(t_1 - sqrt(x)) + t_2) + t_5)) <= 1.0001)
    		tmp = Float64(Float64(Float64(0.5 * sqrt(Float64(1.0 / y))) + Float64(1.0 / Float64(sqrt(x) + t_1))) + Float64(t_3 + t_5));
    	else
    		tmp = Float64(Float64(Float64(1.0 - sqrt(x)) + t_2) + Float64(t_3 + Float64(1.0 / Float64(t_4 + sqrt(z)))));
    	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((1.0 + x));
    	t_2 = sqrt((1.0 + y)) - sqrt(y);
    	t_3 = sqrt((1.0 + t)) - sqrt(t);
    	t_4 = sqrt((z + 1.0));
    	t_5 = t_4 - sqrt(z);
    	tmp = 0.0;
    	if ((t_3 + (((t_1 - sqrt(x)) + t_2) + t_5)) <= 1.0001)
    		tmp = ((0.5 * sqrt((1.0 / y))) + (1.0 / (sqrt(x) + t_1))) + (t_3 + t_5);
    	else
    		tmp = ((1.0 - sqrt(x)) + t_2) + (t_3 + (1.0 / (t_4 + sqrt(z))));
    	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[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$5 = N[(t$95$4 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(t$95$3 + N[(N[(N[(t$95$1 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + t$95$5), $MachinePrecision]), $MachinePrecision], 1.0001], N[(N[(N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$3 + t$95$5), $MachinePrecision]), $MachinePrecision], N[(N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision] + N[(t$95$3 + N[(1.0 / N[(t$95$4 + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]]]
    
    \begin{array}{l}
    [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
    \\
    \begin{array}{l}
    t_1 := \sqrt{1 + x}\\
    t_2 := \sqrt{1 + y} - \sqrt{y}\\
    t_3 := \sqrt{1 + t} - \sqrt{t}\\
    t_4 := \sqrt{z + 1}\\
    t_5 := t\_4 - \sqrt{z}\\
    \mathbf{if}\;t\_3 + \left(\left(\left(t\_1 - \sqrt{x}\right) + t\_2\right) + t\_5\right) \leq 1.0001:\\
    \;\;\;\;\left(0.5 \cdot \sqrt{\frac{1}{y}} + \frac{1}{\sqrt{x} + t\_1}\right) + \left(t\_3 + t\_5\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\left(1 - \sqrt{x}\right) + t\_2\right) + \left(t\_3 + \frac{1}{t\_4 + \sqrt{z}}\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))) < 1.00009999999999999

      1. Initial program 80.6%

        \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. Step-by-step derivation
        1. associate-+l+80.6%

          \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
        2. sub-neg80.6%

          \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
        3. sub-neg80.6%

          \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
        4. +-commutative80.6%

          \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
        5. +-commutative80.6%

          \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
        6. +-commutative80.6%

          \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
      3. Simplified80.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. flip--80.9%

          \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        2. flip--80.8%

          \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        3. frac-add80.9%

          \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      6. Applied egg-rr82.1%

        \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      7. Step-by-step derivation
        1. Simplified87.1%

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        2. Taylor expanded in y around inf 67.2%

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

        if 1.00009999999999999 < (+.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 97.4%

          \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. Step-by-step derivation
          1. associate-+l+97.4%

            \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
          2. sub-neg97.4%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          3. sub-neg97.4%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          4. +-commutative97.4%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          5. +-commutative97.4%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          6. +-commutative97.4%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
        3. Simplified97.4%

          \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
        4. Add Preprocessing
        5. Taylor expanded in x around 0 58.9%

          \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        6. Step-by-step derivation
          1. flip--58.9%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{\sqrt{1 + z} \cdot \sqrt{1 + z} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          2. div-inv58.9%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\left(\sqrt{1 + z} \cdot \sqrt{1 + z} - \sqrt{z} \cdot \sqrt{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          3. add-sqr-sqrt46.4%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\color{blue}{\left(1 + z\right)} - \sqrt{z} \cdot \sqrt{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          4. add-sqr-sqrt59.1%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\left(1 + z\right) - \color{blue}{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        7. Applied egg-rr59.1%

          \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\left(\left(1 + z\right) - z\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        8. Step-by-step derivation
          1. associate-*r/59.1%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{\left(\left(1 + z\right) - z\right) \cdot 1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          2. *-rgt-identity59.1%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{\left(1 + z\right) - z}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          3. associate--l+59.3%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{1 + \left(z - z\right)}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          4. +-inverses59.3%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          5. metadata-eval59.3%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{1}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        9. Simplified59.3%

          \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
      8. Recombined 2 regimes into one program.
      9. Final simplification61.6%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\left(\left(\sqrt{1 + x} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) \leq 1.0001:\\ \;\;\;\;\left(0.5 \cdot \sqrt{\frac{1}{y}} + \frac{1}{\sqrt{x} + \sqrt{1 + x}}\right) + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \frac{1}{\sqrt{z + 1} + \sqrt{z}}\right)\\ \end{array} \]
      10. Add Preprocessing

      Alternative 3: 96.9% accurate, 0.9× speedup?

      \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + t} - \sqrt{t}\\ t_2 := \sqrt{1 + x}\\ t_3 := \sqrt{z + 1}\\ \mathbf{if}\;t\_2 - \sqrt{x} \leq 0.999:\\ \;\;\;\;\frac{1}{\sqrt{x} + t\_2} + \left(t\_1 + \left(t\_3 - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(t\_1 + \frac{1}{t\_3 + \sqrt{z}}\right)\\ \end{array} \end{array} \]
      NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
      (FPCore (x y z t)
       :precision binary64
       (let* ((t_1 (- (sqrt (+ 1.0 t)) (sqrt t)))
              (t_2 (sqrt (+ 1.0 x)))
              (t_3 (sqrt (+ z 1.0))))
         (if (<= (- t_2 (sqrt x)) 0.999)
           (+ (/ 1.0 (+ (sqrt x) t_2)) (+ t_1 (- t_3 (sqrt z))))
           (+
            (+ (- 1.0 (sqrt x)) (- (sqrt (+ 1.0 y)) (sqrt y)))
            (+ t_1 (/ 1.0 (+ t_3 (sqrt z))))))))
      assert(x < y && y < z && z < t);
      double code(double x, double y, double z, double t) {
      	double t_1 = sqrt((1.0 + t)) - sqrt(t);
      	double t_2 = sqrt((1.0 + x));
      	double t_3 = sqrt((z + 1.0));
      	double tmp;
      	if ((t_2 - sqrt(x)) <= 0.999) {
      		tmp = (1.0 / (sqrt(x) + t_2)) + (t_1 + (t_3 - sqrt(z)));
      	} else {
      		tmp = ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y))) + (t_1 + (1.0 / (t_3 + sqrt(z))));
      	}
      	return tmp;
      }
      
      NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
      real(8) function code(x, y, z, t)
          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((1.0d0 + t)) - sqrt(t)
          t_2 = sqrt((1.0d0 + x))
          t_3 = sqrt((z + 1.0d0))
          if ((t_2 - sqrt(x)) <= 0.999d0) then
              tmp = (1.0d0 / (sqrt(x) + t_2)) + (t_1 + (t_3 - sqrt(z)))
          else
              tmp = ((1.0d0 - sqrt(x)) + (sqrt((1.0d0 + y)) - sqrt(y))) + (t_1 + (1.0d0 / (t_3 + sqrt(z))))
          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((1.0 + t)) - Math.sqrt(t);
      	double t_2 = Math.sqrt((1.0 + x));
      	double t_3 = Math.sqrt((z + 1.0));
      	double tmp;
      	if ((t_2 - Math.sqrt(x)) <= 0.999) {
      		tmp = (1.0 / (Math.sqrt(x) + t_2)) + (t_1 + (t_3 - Math.sqrt(z)));
      	} else {
      		tmp = ((1.0 - Math.sqrt(x)) + (Math.sqrt((1.0 + y)) - Math.sqrt(y))) + (t_1 + (1.0 / (t_3 + Math.sqrt(z))));
      	}
      	return tmp;
      }
      
      [x, y, z, t] = sort([x, y, z, t])
      def code(x, y, z, t):
      	t_1 = math.sqrt((1.0 + t)) - math.sqrt(t)
      	t_2 = math.sqrt((1.0 + x))
      	t_3 = math.sqrt((z + 1.0))
      	tmp = 0
      	if (t_2 - math.sqrt(x)) <= 0.999:
      		tmp = (1.0 / (math.sqrt(x) + t_2)) + (t_1 + (t_3 - math.sqrt(z)))
      	else:
      		tmp = ((1.0 - math.sqrt(x)) + (math.sqrt((1.0 + y)) - math.sqrt(y))) + (t_1 + (1.0 / (t_3 + math.sqrt(z))))
      	return tmp
      
      x, y, z, t = sort([x, y, z, t])
      function code(x, y, z, t)
      	t_1 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
      	t_2 = sqrt(Float64(1.0 + x))
      	t_3 = sqrt(Float64(z + 1.0))
      	tmp = 0.0
      	if (Float64(t_2 - sqrt(x)) <= 0.999)
      		tmp = Float64(Float64(1.0 / Float64(sqrt(x) + t_2)) + Float64(t_1 + Float64(t_3 - sqrt(z))));
      	else
      		tmp = Float64(Float64(Float64(1.0 - sqrt(x)) + Float64(sqrt(Float64(1.0 + y)) - sqrt(y))) + Float64(t_1 + Float64(1.0 / Float64(t_3 + sqrt(z)))));
      	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((1.0 + t)) - sqrt(t);
      	t_2 = sqrt((1.0 + x));
      	t_3 = sqrt((z + 1.0));
      	tmp = 0.0;
      	if ((t_2 - sqrt(x)) <= 0.999)
      		tmp = (1.0 / (sqrt(x) + t_2)) + (t_1 + (t_3 - sqrt(z)));
      	else
      		tmp = ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y))) + (t_1 + (1.0 / (t_3 + sqrt(z))));
      	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[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$3 = N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(t$95$2 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], 0.999], N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 + N[(t$95$3 - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 + N[(1.0 / N[(t$95$3 + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
      
      \begin{array}{l}
      [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
      \\
      \begin{array}{l}
      t_1 := \sqrt{1 + t} - \sqrt{t}\\
      t_2 := \sqrt{1 + x}\\
      t_3 := \sqrt{z + 1}\\
      \mathbf{if}\;t\_2 - \sqrt{x} \leq 0.999:\\
      \;\;\;\;\frac{1}{\sqrt{x} + t\_2} + \left(t\_1 + \left(t\_3 - \sqrt{z}\right)\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(t\_1 + \frac{1}{t\_3 + \sqrt{z}}\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) < 0.998999999999999999

        1. Initial program 88.1%

          \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
        2. Step-by-step derivation
          1. associate-+l+88.1%

            \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
          2. sub-neg88.1%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          3. sub-neg88.1%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          4. +-commutative88.1%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          5. +-commutative88.1%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
          6. +-commutative88.1%

            \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
        3. Simplified88.1%

          \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
        4. Add Preprocessing
        5. Step-by-step derivation
          1. flip--88.4%

            \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          2. flip--88.4%

            \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          3. frac-add88.4%

            \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        6. Applied egg-rr89.4%

          \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        7. Step-by-step derivation
          1. Simplified91.9%

            \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          2. Taylor expanded in y around inf 47.6%

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

          if 0.998999999999999999 < (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x))

          1. Initial program 97.6%

            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          2. Step-by-step derivation
            1. associate-+l+97.6%

              \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
            2. sub-neg97.6%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            3. sub-neg97.6%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            4. +-commutative97.6%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            5. +-commutative97.6%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            6. +-commutative97.6%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
          3. Simplified97.6%

            \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
          4. Add Preprocessing
          5. Taylor expanded in x around 0 96.9%

            \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          6. Step-by-step derivation
            1. flip--96.9%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{\sqrt{1 + z} \cdot \sqrt{1 + z} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            2. div-inv96.9%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\left(\sqrt{1 + z} \cdot \sqrt{1 + z} - \sqrt{z} \cdot \sqrt{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            3. add-sqr-sqrt73.7%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\color{blue}{\left(1 + z\right)} - \sqrt{z} \cdot \sqrt{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            4. add-sqr-sqrt97.2%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\left(1 + z\right) - \color{blue}{z}\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          7. Applied egg-rr97.2%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\left(\left(1 + z\right) - z\right) \cdot \frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          8. Step-by-step derivation
            1. associate-*r/97.2%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{\left(\left(1 + z\right) - z\right) \cdot 1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            2. *-rgt-identity97.2%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{\left(1 + z\right) - z}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            3. associate--l+97.5%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{1 + \left(z - z\right)}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            4. +-inverses97.5%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            5. metadata-eval97.5%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{\color{blue}{1}}{\sqrt{1 + z} + \sqrt{z}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          9. Simplified97.5%

            \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\color{blue}{\frac{1}{\sqrt{1 + z} + \sqrt{z}}} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
        8. Recombined 2 regimes into one program.
        9. Final simplification71.2%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\sqrt{1 + x} - \sqrt{x} \leq 0.999:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \frac{1}{\sqrt{z + 1} + \sqrt{z}}\right)\\ \end{array} \]
        10. Add Preprocessing

        Alternative 4: 95.7% accurate, 0.9× speedup?

        \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\\ t_2 := \sqrt{1 + x}\\ \mathbf{if}\;t\_2 - \sqrt{x} \leq 0.999:\\ \;\;\;\;\frac{1}{\sqrt{x} + t\_2} + t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\ \end{array} \end{array} \]
        NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
        (FPCore (x y z t)
         :precision binary64
         (let* ((t_1 (+ (- (sqrt (+ 1.0 t)) (sqrt t)) (- (sqrt (+ z 1.0)) (sqrt z))))
                (t_2 (sqrt (+ 1.0 x))))
           (if (<= (- t_2 (sqrt x)) 0.999)
             (+ (/ 1.0 (+ (sqrt x) t_2)) t_1)
             (+ t_1 (+ (- 1.0 (sqrt x)) (- (sqrt (+ 1.0 y)) (sqrt y)))))))
        assert(x < y && y < z && z < t);
        double code(double x, double y, double z, double t) {
        	double t_1 = (sqrt((1.0 + t)) - sqrt(t)) + (sqrt((z + 1.0)) - sqrt(z));
        	double t_2 = sqrt((1.0 + x));
        	double tmp;
        	if ((t_2 - sqrt(x)) <= 0.999) {
        		tmp = (1.0 / (sqrt(x) + t_2)) + t_1;
        	} else {
        		tmp = t_1 + ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y)));
        	}
        	return tmp;
        }
        
        NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
        real(8) function code(x, y, z, t)
            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) :: tmp
            t_1 = (sqrt((1.0d0 + t)) - sqrt(t)) + (sqrt((z + 1.0d0)) - sqrt(z))
            t_2 = sqrt((1.0d0 + x))
            if ((t_2 - sqrt(x)) <= 0.999d0) then
                tmp = (1.0d0 / (sqrt(x) + t_2)) + t_1
            else
                tmp = t_1 + ((1.0d0 - sqrt(x)) + (sqrt((1.0d0 + y)) - sqrt(y)))
            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((1.0 + t)) - Math.sqrt(t)) + (Math.sqrt((z + 1.0)) - Math.sqrt(z));
        	double t_2 = Math.sqrt((1.0 + x));
        	double tmp;
        	if ((t_2 - Math.sqrt(x)) <= 0.999) {
        		tmp = (1.0 / (Math.sqrt(x) + t_2)) + t_1;
        	} else {
        		tmp = t_1 + ((1.0 - Math.sqrt(x)) + (Math.sqrt((1.0 + y)) - Math.sqrt(y)));
        	}
        	return tmp;
        }
        
        [x, y, z, t] = sort([x, y, z, t])
        def code(x, y, z, t):
        	t_1 = (math.sqrt((1.0 + t)) - math.sqrt(t)) + (math.sqrt((z + 1.0)) - math.sqrt(z))
        	t_2 = math.sqrt((1.0 + x))
        	tmp = 0
        	if (t_2 - math.sqrt(x)) <= 0.999:
        		tmp = (1.0 / (math.sqrt(x) + t_2)) + t_1
        	else:
        		tmp = t_1 + ((1.0 - math.sqrt(x)) + (math.sqrt((1.0 + y)) - math.sqrt(y)))
        	return tmp
        
        x, y, z, t = sort([x, y, z, t])
        function code(x, y, z, t)
        	t_1 = Float64(Float64(sqrt(Float64(1.0 + t)) - sqrt(t)) + Float64(sqrt(Float64(z + 1.0)) - sqrt(z)))
        	t_2 = sqrt(Float64(1.0 + x))
        	tmp = 0.0
        	if (Float64(t_2 - sqrt(x)) <= 0.999)
        		tmp = Float64(Float64(1.0 / Float64(sqrt(x) + t_2)) + t_1);
        	else
        		tmp = Float64(t_1 + Float64(Float64(1.0 - sqrt(x)) + Float64(sqrt(Float64(1.0 + y)) - sqrt(y))));
        	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((1.0 + t)) - sqrt(t)) + (sqrt((z + 1.0)) - sqrt(z));
        	t_2 = sqrt((1.0 + x));
        	tmp = 0.0;
        	if ((t_2 - sqrt(x)) <= 0.999)
        		tmp = (1.0 / (sqrt(x) + t_2)) + t_1;
        	else
        		tmp = t_1 + ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y)));
        	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[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(t$95$2 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], 0.999], N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision], N[(t$95$1 + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
        
        \begin{array}{l}
        [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
        \\
        \begin{array}{l}
        t_1 := \left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\\
        t_2 := \sqrt{1 + x}\\
        \mathbf{if}\;t\_2 - \sqrt{x} \leq 0.999:\\
        \;\;\;\;\frac{1}{\sqrt{x} + t\_2} + t\_1\\
        
        \mathbf{else}:\\
        \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x)) < 0.998999999999999999

          1. Initial program 88.1%

            \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
          2. Step-by-step derivation
            1. associate-+l+88.1%

              \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
            2. sub-neg88.1%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            3. sub-neg88.1%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            4. +-commutative88.1%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            5. +-commutative88.1%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
            6. +-commutative88.1%

              \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
          3. Simplified88.1%

            \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
          4. Add Preprocessing
          5. Step-by-step derivation
            1. flip--88.4%

              \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            2. flip--88.4%

              \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            3. frac-add88.4%

              \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          6. Applied egg-rr89.4%

            \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          7. Step-by-step derivation
            1. Simplified91.9%

              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            2. Taylor expanded in y around inf 47.6%

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

            if 0.998999999999999999 < (-.f64 (sqrt.f64 (+.f64 x #s(literal 1 binary64))) (sqrt.f64 x))

            1. Initial program 97.6%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. associate-+l+97.6%

                \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
              2. sub-neg97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              3. sub-neg97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              4. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              5. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              6. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
            3. Simplified97.6%

              \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
            4. Add Preprocessing
            5. Taylor expanded in x around 0 96.9%

              \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
          8. Recombined 2 regimes into one program.
          9. Final simplification70.9%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\sqrt{1 + x} - \sqrt{x} \leq 0.999:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\ \end{array} \]
          10. Add Preprocessing

          Alternative 5: 96.2% accurate, 1.1× speedup?

          \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + t}\\ t_2 := \sqrt{z + 1} - \sqrt{z}\\ \mathbf{if}\;x \leq 8.5 \cdot 10^{-7}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{1}{t\_1 + \sqrt{t}} + t\_2\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(t\_1 - \sqrt{t}\right) + t\_2\right)\\ \end{array} \end{array} \]
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (sqrt (+ 1.0 t))) (t_2 (- (sqrt (+ z 1.0)) (sqrt z))))
             (if (<= x 8.5e-7)
               (+
                (+ (- 1.0 (sqrt x)) (- (sqrt (+ 1.0 y)) (sqrt y)))
                (+ (/ 1.0 (+ t_1 (sqrt t))) t_2))
               (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) (+ (- t_1 (sqrt t)) t_2)))))
          assert(x < y && y < z && z < t);
          double code(double x, double y, double z, double t) {
          	double t_1 = sqrt((1.0 + t));
          	double t_2 = sqrt((z + 1.0)) - sqrt(z);
          	double tmp;
          	if (x <= 8.5e-7) {
          		tmp = ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y))) + ((1.0 / (t_1 + sqrt(t))) + t_2);
          	} else {
          		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + ((t_1 - sqrt(t)) + t_2);
          	}
          	return tmp;
          }
          
          NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
          real(8) function code(x, y, z, t)
              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) :: tmp
              t_1 = sqrt((1.0d0 + t))
              t_2 = sqrt((z + 1.0d0)) - sqrt(z)
              if (x <= 8.5d-7) then
                  tmp = ((1.0d0 - sqrt(x)) + (sqrt((1.0d0 + y)) - sqrt(y))) + ((1.0d0 / (t_1 + sqrt(t))) + t_2)
              else
                  tmp = (1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + ((t_1 - sqrt(t)) + 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((1.0 + t));
          	double t_2 = Math.sqrt((z + 1.0)) - Math.sqrt(z);
          	double tmp;
          	if (x <= 8.5e-7) {
          		tmp = ((1.0 - Math.sqrt(x)) + (Math.sqrt((1.0 + y)) - Math.sqrt(y))) + ((1.0 / (t_1 + Math.sqrt(t))) + t_2);
          	} else {
          		tmp = (1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + ((t_1 - Math.sqrt(t)) + t_2);
          	}
          	return tmp;
          }
          
          [x, y, z, t] = sort([x, y, z, t])
          def code(x, y, z, t):
          	t_1 = math.sqrt((1.0 + t))
          	t_2 = math.sqrt((z + 1.0)) - math.sqrt(z)
          	tmp = 0
          	if x <= 8.5e-7:
          		tmp = ((1.0 - math.sqrt(x)) + (math.sqrt((1.0 + y)) - math.sqrt(y))) + ((1.0 / (t_1 + math.sqrt(t))) + t_2)
          	else:
          		tmp = (1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + ((t_1 - math.sqrt(t)) + t_2)
          	return tmp
          
          x, y, z, t = sort([x, y, z, t])
          function code(x, y, z, t)
          	t_1 = sqrt(Float64(1.0 + t))
          	t_2 = Float64(sqrt(Float64(z + 1.0)) - sqrt(z))
          	tmp = 0.0
          	if (x <= 8.5e-7)
          		tmp = Float64(Float64(Float64(1.0 - sqrt(x)) + Float64(sqrt(Float64(1.0 + y)) - sqrt(y))) + Float64(Float64(1.0 / Float64(t_1 + sqrt(t))) + t_2));
          	else
          		tmp = Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + Float64(Float64(t_1 - sqrt(t)) + 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((1.0 + t));
          	t_2 = sqrt((z + 1.0)) - sqrt(z);
          	tmp = 0.0;
          	if (x <= 8.5e-7)
          		tmp = ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y))) + ((1.0 / (t_1 + sqrt(t))) + t_2);
          	else
          		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + ((t_1 - sqrt(t)) + 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[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 8.5e-7], N[(N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 / N[(t$95$1 + N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(t$95$1 - N[Sqrt[t], $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision]]]]
          
          \begin{array}{l}
          [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
          \\
          \begin{array}{l}
          t_1 := \sqrt{1 + t}\\
          t_2 := \sqrt{z + 1} - \sqrt{z}\\
          \mathbf{if}\;x \leq 8.5 \cdot 10^{-7}:\\
          \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{1}{t\_1 + \sqrt{t}} + t\_2\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(t\_1 - \sqrt{t}\right) + t\_2\right)\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if x < 8.50000000000000014e-7

            1. Initial program 97.6%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. associate-+l+97.6%

                \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
              2. sub-neg97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              3. sub-neg97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              4. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              5. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              6. +-commutative97.6%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
            3. Simplified97.6%

              \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
            4. Add Preprocessing
            5. Taylor expanded in x around 0 96.9%

              \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            6. Step-by-step derivation
              1. flip--97.0%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\frac{\sqrt{1 + t} \cdot \sqrt{1 + t} - \sqrt{t} \cdot \sqrt{t}}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
              2. div-inv97.0%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\left(\sqrt{1 + t} \cdot \sqrt{1 + t} - \sqrt{t} \cdot \sqrt{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
              3. add-sqr-sqrt65.9%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\color{blue}{\left(1 + t\right)} - \sqrt{t} \cdot \sqrt{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}\right) \]
              4. add-sqr-sqrt97.0%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\left(1 + t\right) - \color{blue}{t}\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}\right) \]
            7. Applied egg-rr97.0%

              \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\left(\left(1 + t\right) - t\right) \cdot \frac{1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
            8. Step-by-step derivation
              1. associate-*r/97.0%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \color{blue}{\frac{\left(\left(1 + t\right) - t\right) \cdot 1}{\sqrt{1 + t} + \sqrt{t}}}\right) \]
              2. *-rgt-identity97.0%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{\left(1 + t\right) - t}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
              3. associate--l+97.8%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{1 + \left(t - t\right)}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
              4. +-inverses97.8%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
              5. metadata-eval97.8%

                \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \frac{\color{blue}{1}}{\sqrt{1 + t} + \sqrt{t}}\right) \]
            9. Simplified97.8%

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

            if 8.50000000000000014e-7 < x

            1. Initial program 88.1%

              \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
            2. Step-by-step derivation
              1. associate-+l+88.1%

                \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
              2. sub-neg88.1%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              3. sub-neg88.1%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              4. +-commutative88.1%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              5. +-commutative88.1%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
              6. +-commutative88.1%

                \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
            3. Simplified88.1%

              \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
            4. Add Preprocessing
            5. Step-by-step derivation
              1. flip--88.4%

                \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              2. flip--88.4%

                \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              3. frac-add88.4%

                \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            6. Applied egg-rr89.4%

              \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            7. Step-by-step derivation
              1. Simplified91.9%

                \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              2. Taylor expanded in y around inf 47.6%

                \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
            8. Recombined 2 regimes into one program.
            9. Final simplification71.3%

              \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 8.5 \cdot 10^{-7}:\\ \;\;\;\;\left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\frac{1}{\sqrt{1 + t} + \sqrt{t}} + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \end{array} \]
            10. Add Preprocessing

            Alternative 6: 95.8% accurate, 1.1× speedup?

            \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\\ \mathbf{if}\;y \leq 1.5 \cdot 10^{+22}:\\ \;\;\;\;t\_1 + \left(1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + t\_1\\ \end{array} \end{array} \]
            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 (+ 1.0 t)) (sqrt t)) (- (sqrt (+ z 1.0)) (sqrt z)))))
               (if (<= y 1.5e+22)
                 (+ t_1 (+ 1.0 (- (sqrt (+ 1.0 y)) (+ (sqrt x) (sqrt y)))))
                 (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) t_1))))
            assert(x < y && y < z && z < t);
            double code(double x, double y, double z, double t) {
            	double t_1 = (sqrt((1.0 + t)) - sqrt(t)) + (sqrt((z + 1.0)) - sqrt(z));
            	double tmp;
            	if (y <= 1.5e+22) {
            		tmp = t_1 + (1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y))));
            	} else {
            		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + t_1;
            	}
            	return tmp;
            }
            
            NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
            real(8) function code(x, y, z, t)
                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) :: tmp
                t_1 = (sqrt((1.0d0 + t)) - sqrt(t)) + (sqrt((z + 1.0d0)) - sqrt(z))
                if (y <= 1.5d+22) then
                    tmp = t_1 + (1.0d0 + (sqrt((1.0d0 + y)) - (sqrt(x) + sqrt(y))))
                else
                    tmp = (1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + 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((1.0 + t)) - Math.sqrt(t)) + (Math.sqrt((z + 1.0)) - Math.sqrt(z));
            	double tmp;
            	if (y <= 1.5e+22) {
            		tmp = t_1 + (1.0 + (Math.sqrt((1.0 + y)) - (Math.sqrt(x) + Math.sqrt(y))));
            	} else {
            		tmp = (1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + t_1;
            	}
            	return tmp;
            }
            
            [x, y, z, t] = sort([x, y, z, t])
            def code(x, y, z, t):
            	t_1 = (math.sqrt((1.0 + t)) - math.sqrt(t)) + (math.sqrt((z + 1.0)) - math.sqrt(z))
            	tmp = 0
            	if y <= 1.5e+22:
            		tmp = t_1 + (1.0 + (math.sqrt((1.0 + y)) - (math.sqrt(x) + math.sqrt(y))))
            	else:
            		tmp = (1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + t_1
            	return tmp
            
            x, y, z, t = sort([x, y, z, t])
            function code(x, y, z, t)
            	t_1 = Float64(Float64(sqrt(Float64(1.0 + t)) - sqrt(t)) + Float64(sqrt(Float64(z + 1.0)) - sqrt(z)))
            	tmp = 0.0
            	if (y <= 1.5e+22)
            		tmp = Float64(t_1 + Float64(1.0 + Float64(sqrt(Float64(1.0 + y)) - Float64(sqrt(x) + sqrt(y)))));
            	else
            		tmp = Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + 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((1.0 + t)) - sqrt(t)) + (sqrt((z + 1.0)) - sqrt(z));
            	tmp = 0.0;
            	if (y <= 1.5e+22)
            		tmp = t_1 + (1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y))));
            	else
            		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + 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[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, 1.5e+22], N[(t$95$1 + N[(1.0 + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $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 := \left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\\
            \mathbf{if}\;y \leq 1.5 \cdot 10^{+22}:\\
            \;\;\;\;t\_1 + \left(1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + t\_1\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if y < 1.5e22

              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. associate-+l+96.7%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                2. sub-neg96.7%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                3. sub-neg96.7%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                4. +-commutative96.7%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                5. +-commutative96.7%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                6. +-commutative96.7%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
              3. Simplified96.7%

                \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
              4. Add Preprocessing
              5. Taylor expanded in x around 0 48.0%

                \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              6. Step-by-step derivation
                1. associate--l+48.1%

                  \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\right)} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              7. Simplified48.1%

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

              if 1.5e22 < y

              1. Initial program 87.5%

                \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
              2. Step-by-step derivation
                1. associate-+l+87.5%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                2. sub-neg87.5%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                3. sub-neg87.5%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                4. +-commutative87.5%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                5. +-commutative87.5%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                6. +-commutative87.5%

                  \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
              3. Simplified87.5%

                \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
              4. Add Preprocessing
              5. Step-by-step derivation
                1. flip--87.9%

                  \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                2. flip--87.9%

                  \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                3. frac-add87.9%

                  \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              6. Applied egg-rr88.7%

                \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              7. Step-by-step derivation
                1. Simplified92.2%

                  \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                2. Taylor expanded in y around inf 90.1%

                  \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
              8. Recombined 2 regimes into one program.
              9. Final simplification67.0%

                \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 1.5 \cdot 10^{+22}:\\ \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \end{array} \]
              10. Add Preprocessing

              Alternative 7: 96.5% accurate, 1.3× speedup?

              \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ t_2 := \left(\sqrt{1 + t} - \sqrt{t}\right) + t\_1\\ \mathbf{if}\;y \leq 5 \cdot 10^{-63}:\\ \;\;\;\;t\_2 + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{elif}\;y \leq 6.3 \cdot 10^{+29}:\\ \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + t\_2\\ \end{array} \end{array} \]
              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 (+ 1.0 t)) (sqrt t)) t_1)))
                 (if (<= y 5e-63)
                   (+ t_2 (- 2.0 (+ (sqrt x) (sqrt y))))
                   (if (<= y 6.3e+29)
                     (+ t_1 (+ (- 1.0 (sqrt x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))))
                     (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) 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((1.0 + t)) - sqrt(t)) + t_1;
              	double tmp;
              	if (y <= 5e-63) {
              		tmp = t_2 + (2.0 - (sqrt(x) + sqrt(y)));
              	} else if (y <= 6.3e+29) {
              		tmp = t_1 + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
              	} else {
              		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + t_2;
              	}
              	return tmp;
              }
              
              NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
              real(8) function code(x, y, z, t)
                  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) :: tmp
                  t_1 = sqrt((z + 1.0d0)) - sqrt(z)
                  t_2 = (sqrt((1.0d0 + t)) - sqrt(t)) + t_1
                  if (y <= 5d-63) then
                      tmp = t_2 + (2.0d0 - (sqrt(x) + sqrt(y)))
                  else if (y <= 6.3d+29) then
                      tmp = t_1 + ((1.0d0 - sqrt(x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y)))))
                  else
                      tmp = (1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + 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((1.0 + t)) - Math.sqrt(t)) + t_1;
              	double tmp;
              	if (y <= 5e-63) {
              		tmp = t_2 + (2.0 - (Math.sqrt(x) + Math.sqrt(y)));
              	} else if (y <= 6.3e+29) {
              		tmp = t_1 + ((1.0 - Math.sqrt(x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y)))));
              	} else {
              		tmp = (1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + 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((1.0 + t)) - math.sqrt(t)) + t_1
              	tmp = 0
              	if y <= 5e-63:
              		tmp = t_2 + (2.0 - (math.sqrt(x) + math.sqrt(y)))
              	elif y <= 6.3e+29:
              		tmp = t_1 + ((1.0 - math.sqrt(x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y)))))
              	else:
              		tmp = (1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + 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(Float64(sqrt(Float64(1.0 + t)) - sqrt(t)) + t_1)
              	tmp = 0.0
              	if (y <= 5e-63)
              		tmp = Float64(t_2 + Float64(2.0 - Float64(sqrt(x) + sqrt(y))));
              	elseif (y <= 6.3e+29)
              		tmp = Float64(t_1 + Float64(Float64(1.0 - sqrt(x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))));
              	else
              		tmp = Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + 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((1.0 + t)) - sqrt(t)) + t_1;
              	tmp = 0.0;
              	if (y <= 5e-63)
              		tmp = t_2 + (2.0 - (sqrt(x) + sqrt(y)));
              	elseif (y <= 6.3e+29)
              		tmp = t_1 + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
              	else
              		tmp = (1.0 / (sqrt(x) + sqrt((1.0 + x)))) + 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[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision]}, If[LessEqual[y, 5e-63], N[(t$95$2 + N[(2.0 - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 6.3e+29], N[(t$95$1 + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $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 := \left(\sqrt{1 + t} - \sqrt{t}\right) + t\_1\\
              \mathbf{if}\;y \leq 5 \cdot 10^{-63}:\\
              \;\;\;\;t\_2 + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
              
              \mathbf{elif}\;y \leq 6.3 \cdot 10^{+29}:\\
              \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + t\_2\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 3 regimes
              2. if y < 5.0000000000000002e-63

                1. Initial program 96.9%

                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. Step-by-step derivation
                  1. associate-+l+96.9%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                  2. sub-neg96.9%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  3. sub-neg96.9%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  4. +-commutative96.9%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  5. +-commutative96.9%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  6. +-commutative96.9%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                3. Simplified96.9%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                4. Add Preprocessing
                5. Taylor expanded in x around 0 48.6%

                  \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                6. Taylor expanded in y around 0 48.6%

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

                if 5.0000000000000002e-63 < y < 6.2999999999999998e29

                1. Initial program 93.2%

                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. Step-by-step derivation
                  1. associate-+l+93.2%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                  2. sub-neg93.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  3. sub-neg93.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  4. +-commutative93.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  5. +-commutative93.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  6. +-commutative93.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                3. Simplified93.2%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                4. Add Preprocessing
                5. Taylor expanded in x around 0 49.1%

                  \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                6. Step-by-step derivation
                  1. flip--49.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  2. div-inv49.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  3. add-sqr-sqrt46.9%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  4. add-sqr-sqrt49.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\left(1 + y\right) - \color{blue}{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                7. Applied egg-rr49.1%

                  \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\left(1 + y\right) - y\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                8. Step-by-step derivation
                  1. associate-*r/49.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\left(\left(1 + y\right) - y\right) \cdot 1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  2. *-rgt-identity49.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{\left(1 + y\right) - y}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  3. associate--l+50.9%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  4. +-inverses50.9%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  5. metadata-eval50.9%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                9. Simplified50.9%

                  \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                10. Taylor expanded in t around inf 42.3%

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

                if 6.2999999999999998e29 < y

                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. associate-+l+88.2%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                  2. sub-neg88.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  3. sub-neg88.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  4. +-commutative88.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  5. +-commutative88.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  6. +-commutative88.2%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                3. Simplified88.2%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                4. Add Preprocessing
                5. Step-by-step derivation
                  1. flip--88.7%

                    \[\leadsto \left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  2. flip--88.7%

                    \[\leadsto \left(\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  3. frac-add88.7%

                    \[\leadsto \color{blue}{\frac{\left(\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                6. Applied egg-rr89.4%

                  \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) - x\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right) + \left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\left(1 + y\right) - y\right)}{\left(\sqrt{x + 1} + \sqrt{x}\right) \cdot \left(\sqrt{1 + y} + \sqrt{y}\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                7. Step-by-step derivation
                  1. Simplified91.7%

                    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x + \left(1 - x\right), \sqrt{1 + y} + \sqrt{y}, \sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}{\left(\sqrt{1 + y} + \sqrt{y}\right) \cdot \left(\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)\right)}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  2. Taylor expanded in y around inf 91.0%

                    \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                8. Recombined 3 regimes into one program.
                9. Final simplification65.4%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{-63}:\\ \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{elif}\;y \leq 6.3 \cdot 10^{+29}:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \sqrt{1 + x}} + \left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\\ \end{array} \]
                10. Add Preprocessing

                Alternative 8: 91.2% accurate, 1.3× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{z + 1} - \sqrt{z}\\ \mathbf{if}\;y \leq 10^{-63}:\\ \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + t\_1\right) + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (let* ((t_1 (- (sqrt (+ z 1.0)) (sqrt z))))
                   (if (<= y 1e-63)
                     (+ (+ (- (sqrt (+ 1.0 t)) (sqrt t)) t_1) (- 2.0 (+ (sqrt x) (sqrt y))))
                     (+ t_1 (+ (- 1.0 (sqrt x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y)))))))))
                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 tmp;
                	if (y <= 1e-63) {
                		tmp = ((sqrt((1.0 + t)) - sqrt(t)) + t_1) + (2.0 - (sqrt(x) + sqrt(y)));
                	} else {
                		tmp = t_1 + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    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) :: tmp
                    t_1 = sqrt((z + 1.0d0)) - sqrt(z)
                    if (y <= 1d-63) then
                        tmp = ((sqrt((1.0d0 + t)) - sqrt(t)) + t_1) + (2.0d0 - (sqrt(x) + sqrt(y)))
                    else
                        tmp = t_1 + ((1.0d0 - sqrt(x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y)))))
                    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 tmp;
                	if (y <= 1e-63) {
                		tmp = ((Math.sqrt((1.0 + t)) - Math.sqrt(t)) + t_1) + (2.0 - (Math.sqrt(x) + Math.sqrt(y)));
                	} else {
                		tmp = t_1 + ((1.0 - Math.sqrt(x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y)))));
                	}
                	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)
                	tmp = 0
                	if y <= 1e-63:
                		tmp = ((math.sqrt((1.0 + t)) - math.sqrt(t)) + t_1) + (2.0 - (math.sqrt(x) + math.sqrt(y)))
                	else:
                		tmp = t_1 + ((1.0 - math.sqrt(x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y)))))
                	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))
                	tmp = 0.0
                	if (y <= 1e-63)
                		tmp = Float64(Float64(Float64(sqrt(Float64(1.0 + t)) - sqrt(t)) + t_1) + Float64(2.0 - Float64(sqrt(x) + sqrt(y))));
                	else
                		tmp = Float64(t_1 + Float64(Float64(1.0 - sqrt(x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))));
                	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);
                	tmp = 0.0;
                	if (y <= 1e-63)
                		tmp = ((sqrt((1.0 + t)) - sqrt(t)) + t_1) + (2.0 - (sqrt(x) + sqrt(y)));
                	else
                		tmp = t_1 + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
                	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]}, If[LessEqual[y, 1e-63], N[(N[(N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + N[(2.0 - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$1 + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                t_1 := \sqrt{z + 1} - \sqrt{z}\\
                \mathbf{if}\;y \leq 10^{-63}:\\
                \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + t\_1\right) + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;t\_1 + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if y < 1.00000000000000007e-63

                  1. Initial program 96.9%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+96.9%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified96.9%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in x around 0 48.6%

                    \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  6. Taylor expanded in y around 0 48.6%

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

                  if 1.00000000000000007e-63 < y

                  1. Initial program 89.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+89.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg89.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg89.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative89.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative89.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative89.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified89.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in x around 0 45.5%

                    \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  6. Step-by-step derivation
                    1. flip--45.5%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    2. div-inv45.5%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    3. add-sqr-sqrt37.2%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    4. add-sqr-sqrt45.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\left(1 + y\right) - \color{blue}{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  7. Applied egg-rr45.6%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\left(1 + y\right) - y\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  8. Step-by-step derivation
                    1. associate-*r/45.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\left(\left(1 + y\right) - y\right) \cdot 1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    2. *-rgt-identity45.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{\left(1 + y\right) - y}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    3. associate--l+46.1%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    4. +-inverses46.1%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    5. metadata-eval46.1%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  9. Simplified46.1%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  10. Taylor expanded in t around inf 31.7%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \color{blue}{\left(\sqrt{1 + z} - \sqrt{z}\right)} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification38.5%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 10^{-63}:\\ \;\;\;\;\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(2 - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \end{array} \]
                5. Add Preprocessing

                Alternative 9: 91.0% accurate, 1.6× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 0.96:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 0.96)
                   (+
                    (- (sqrt (+ z 1.0)) (sqrt z))
                    (+ (- 1.0 (sqrt x)) (/ 1.0 (+ (sqrt y) (sqrt (+ 1.0 y))))))
                   (/ (+ (* -0.125 (sqrt (/ 1.0 x))) (* 0.5 (sqrt x))) x)))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 0.96) {
                		tmp = (sqrt((z + 1.0)) - sqrt(z)) + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
                	} else {
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 0.96d0) then
                        tmp = (sqrt((z + 1.0d0)) - sqrt(z)) + ((1.0d0 - sqrt(x)) + (1.0d0 / (sqrt(y) + sqrt((1.0d0 + y)))))
                    else
                        tmp = (((-0.125d0) * sqrt((1.0d0 / x))) + (0.5d0 * sqrt(x))) / 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 (x <= 0.96) {
                		tmp = (Math.sqrt((z + 1.0)) - Math.sqrt(z)) + ((1.0 - Math.sqrt(x)) + (1.0 / (Math.sqrt(y) + Math.sqrt((1.0 + y)))));
                	} else {
                		tmp = ((-0.125 * Math.sqrt((1.0 / x))) + (0.5 * Math.sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 0.96:
                		tmp = (math.sqrt((z + 1.0)) - math.sqrt(z)) + ((1.0 - math.sqrt(x)) + (1.0 / (math.sqrt(y) + math.sqrt((1.0 + y)))))
                	else:
                		tmp = ((-0.125 * math.sqrt((1.0 / x))) + (0.5 * math.sqrt(x))) / x
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 0.96)
                		tmp = Float64(Float64(sqrt(Float64(z + 1.0)) - sqrt(z)) + Float64(Float64(1.0 - sqrt(x)) + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(1.0 + y))))));
                	else
                		tmp = Float64(Float64(Float64(-0.125 * sqrt(Float64(1.0 / x))) + Float64(0.5 * sqrt(x))) / 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 (x <= 0.96)
                		tmp = (sqrt((z + 1.0)) - sqrt(z)) + ((1.0 - sqrt(x)) + (1.0 / (sqrt(y) + sqrt((1.0 + y)))));
                	else
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / 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[x, 0.96], N[(N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(-0.125 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 0.96:\\
                \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 0.95999999999999996

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in x around 0 96.5%

                    \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  6. Step-by-step derivation
                    1. flip--96.5%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    2. div-inv96.5%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    3. add-sqr-sqrt85.9%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    4. add-sqr-sqrt96.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \left(\left(1 + y\right) - \color{blue}{y}\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  7. Applied egg-rr96.6%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\left(\left(1 + y\right) - y\right) \cdot \frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  8. Step-by-step derivation
                    1. associate-*r/96.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{\left(\left(1 + y\right) - y\right) \cdot 1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    2. *-rgt-identity96.6%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{\left(1 + y\right) - y}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    3. associate--l+97.2%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    4. +-inverses97.2%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                    5. metadata-eval97.2%

                      \[\leadsto \left(\left(1 - \sqrt{x}\right) + \frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  9. Simplified97.2%

                    \[\leadsto \left(\left(1 - \sqrt{x}\right) + \color{blue}{\frac{1}{\sqrt{1 + y} + \sqrt{y}}}\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  10. Taylor expanded in t around inf 63.9%

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

                  if 0.95999999999999996 < x

                  1. Initial program 88.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+88.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified88.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification34.9%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.96:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\ \end{array} \]
                5. Add Preprocessing

                Alternative 10: 89.9% accurate, 1.6× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 1.0)
                   (+
                    (- (sqrt (+ z 1.0)) (sqrt z))
                    (+ (- 1.0 (sqrt x)) (- (sqrt (+ 1.0 y)) (sqrt y))))
                   (/ (+ (* -0.125 (sqrt (/ 1.0 x))) (* 0.5 (sqrt x))) x)))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 1.0) {
                		tmp = (sqrt((z + 1.0)) - sqrt(z)) + ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y)));
                	} else {
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 1.0d0) then
                        tmp = (sqrt((z + 1.0d0)) - sqrt(z)) + ((1.0d0 - sqrt(x)) + (sqrt((1.0d0 + y)) - sqrt(y)))
                    else
                        tmp = (((-0.125d0) * sqrt((1.0d0 / x))) + (0.5d0 * sqrt(x))) / 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 (x <= 1.0) {
                		tmp = (Math.sqrt((z + 1.0)) - Math.sqrt(z)) + ((1.0 - Math.sqrt(x)) + (Math.sqrt((1.0 + y)) - Math.sqrt(y)));
                	} else {
                		tmp = ((-0.125 * Math.sqrt((1.0 / x))) + (0.5 * Math.sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 1.0:
                		tmp = (math.sqrt((z + 1.0)) - math.sqrt(z)) + ((1.0 - math.sqrt(x)) + (math.sqrt((1.0 + y)) - math.sqrt(y)))
                	else:
                		tmp = ((-0.125 * math.sqrt((1.0 / x))) + (0.5 * math.sqrt(x))) / x
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 1.0)
                		tmp = Float64(Float64(sqrt(Float64(z + 1.0)) - sqrt(z)) + Float64(Float64(1.0 - sqrt(x)) + Float64(sqrt(Float64(1.0 + y)) - sqrt(y))));
                	else
                		tmp = Float64(Float64(Float64(-0.125 * sqrt(Float64(1.0 / x))) + Float64(0.5 * sqrt(x))) / 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 (x <= 1.0)
                		tmp = (sqrt((z + 1.0)) - sqrt(z)) + ((1.0 - sqrt(x)) + (sqrt((1.0 + y)) - sqrt(y)));
                	else
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / 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[x, 1.0], N[(N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(-0.125 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 1:\\
                \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 1

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in x around 0 96.5%

                    \[\leadsto \left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) \]
                  6. Taylor expanded in t around inf 63.5%

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

                  if 1 < x

                  1. Initial program 88.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+88.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified88.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification34.7%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\left(1 - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\ \end{array} \]
                5. Add Preprocessing

                Alternative 11: 85.9% accurate, 2.0× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;z \leq 1400000:\\ \;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + 0.5 \cdot y\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \end{array} \end{array} \]
                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 1400000.0)
                   (-
                    (+ (+ (sqrt (+ z 1.0)) 2.0) (* 0.5 y))
                    (+ (sqrt x) (+ (sqrt y) (sqrt z))))
                   (+
                    1.0
                    (- (+ (sqrt (+ 1.0 y)) (* 0.5 (sqrt (/ 1.0 z)))) (+ (sqrt x) (sqrt y))))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (z <= 1400000.0) {
                		tmp = ((sqrt((z + 1.0)) + 2.0) + (0.5 * y)) - (sqrt(x) + (sqrt(y) + sqrt(z)));
                	} else {
                		tmp = 1.0 + ((sqrt((1.0 + y)) + (0.5 * sqrt((1.0 / z)))) - (sqrt(x) + sqrt(y)));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    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 <= 1400000.0d0) then
                        tmp = ((sqrt((z + 1.0d0)) + 2.0d0) + (0.5d0 * y)) - (sqrt(x) + (sqrt(y) + sqrt(z)))
                    else
                        tmp = 1.0d0 + ((sqrt((1.0d0 + y)) + (0.5d0 * sqrt((1.0d0 / z)))) - (sqrt(x) + sqrt(y)))
                    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 <= 1400000.0) {
                		tmp = ((Math.sqrt((z + 1.0)) + 2.0) + (0.5 * y)) - (Math.sqrt(x) + (Math.sqrt(y) + Math.sqrt(z)));
                	} else {
                		tmp = 1.0 + ((Math.sqrt((1.0 + y)) + (0.5 * Math.sqrt((1.0 / z)))) - (Math.sqrt(x) + Math.sqrt(y)));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if z <= 1400000.0:
                		tmp = ((math.sqrt((z + 1.0)) + 2.0) + (0.5 * y)) - (math.sqrt(x) + (math.sqrt(y) + math.sqrt(z)))
                	else:
                		tmp = 1.0 + ((math.sqrt((1.0 + y)) + (0.5 * math.sqrt((1.0 / z)))) - (math.sqrt(x) + math.sqrt(y)))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (z <= 1400000.0)
                		tmp = Float64(Float64(Float64(sqrt(Float64(z + 1.0)) + 2.0) + Float64(0.5 * y)) - Float64(sqrt(x) + Float64(sqrt(y) + sqrt(z))));
                	else
                		tmp = Float64(1.0 + Float64(Float64(sqrt(Float64(1.0 + y)) + Float64(0.5 * sqrt(Float64(1.0 / z)))) - Float64(sqrt(x) + sqrt(y))));
                	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 <= 1400000.0)
                		tmp = ((sqrt((z + 1.0)) + 2.0) + (0.5 * y)) - (sqrt(x) + (sqrt(y) + sqrt(z)));
                	else
                		tmp = 1.0 + ((sqrt((1.0 + y)) + (0.5 * sqrt((1.0 / z)))) - (sqrt(x) + sqrt(y)));
                	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, 1400000.0], N[(N[(N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] + 2.0), $MachinePrecision] + N[(0.5 * y), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;z \leq 1400000:\\
                \;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + 0.5 \cdot y\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if z < 1.4e6

                  1. Initial program 97.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.2%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+30.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified30.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around 0 23.5%

                    \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  9. Taylor expanded in y around 0 22.3%

                    \[\leadsto \color{blue}{\left(2 + \left(\sqrt{1 + z} + 0.5 \cdot y\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  10. Step-by-step derivation
                    1. associate-+r+22.3%

                      \[\leadsto \color{blue}{\left(\left(2 + \sqrt{1 + z}\right) + 0.5 \cdot y\right)} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
                    2. +-commutative22.3%

                      \[\leadsto \left(\color{blue}{\left(\sqrt{1 + z} + 2\right)} + 0.5 \cdot y\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
                    3. *-commutative22.3%

                      \[\leadsto \left(\left(\sqrt{1 + z} + 2\right) + \color{blue}{y \cdot 0.5}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right) \]
                  11. Simplified22.3%

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

                  if 1.4e6 < z

                  1. Initial program 87.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+87.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified87.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 4.3%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+19.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified19.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in z around inf 20.4%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right)\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  9. Step-by-step derivation
                    1. associate--l+30.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  10. Simplified30.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  11. Taylor expanded in x around 0 17.2%

                    \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right)\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  12. Step-by-step derivation
                    1. associate--l+31.4%

                      \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  13. Simplified31.4%

                    \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification26.6%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 1400000:\\ \;\;\;\;\left(\left(\sqrt{z + 1} + 2\right) + 0.5 \cdot y\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \end{array} \]
                5. Add Preprocessing

                Alternative 12: 85.8% accurate, 2.0× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;z \leq 450000:\\ \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \end{array} \end{array} \]
                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 450000.0)
                   (+ 2.0 (- (sqrt (+ z 1.0)) (+ (sqrt x) (+ (sqrt y) (sqrt z)))))
                   (+
                    1.0
                    (- (+ (sqrt (+ 1.0 y)) (* 0.5 (sqrt (/ 1.0 z)))) (+ (sqrt x) (sqrt y))))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (z <= 450000.0) {
                		tmp = 2.0 + (sqrt((z + 1.0)) - (sqrt(x) + (sqrt(y) + sqrt(z))));
                	} else {
                		tmp = 1.0 + ((sqrt((1.0 + y)) + (0.5 * sqrt((1.0 / z)))) - (sqrt(x) + sqrt(y)));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    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 <= 450000.0d0) then
                        tmp = 2.0d0 + (sqrt((z + 1.0d0)) - (sqrt(x) + (sqrt(y) + sqrt(z))))
                    else
                        tmp = 1.0d0 + ((sqrt((1.0d0 + y)) + (0.5d0 * sqrt((1.0d0 / z)))) - (sqrt(x) + sqrt(y)))
                    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 <= 450000.0) {
                		tmp = 2.0 + (Math.sqrt((z + 1.0)) - (Math.sqrt(x) + (Math.sqrt(y) + Math.sqrt(z))));
                	} else {
                		tmp = 1.0 + ((Math.sqrt((1.0 + y)) + (0.5 * Math.sqrt((1.0 / z)))) - (Math.sqrt(x) + Math.sqrt(y)));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if z <= 450000.0:
                		tmp = 2.0 + (math.sqrt((z + 1.0)) - (math.sqrt(x) + (math.sqrt(y) + math.sqrt(z))))
                	else:
                		tmp = 1.0 + ((math.sqrt((1.0 + y)) + (0.5 * math.sqrt((1.0 / z)))) - (math.sqrt(x) + math.sqrt(y)))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (z <= 450000.0)
                		tmp = Float64(2.0 + Float64(sqrt(Float64(z + 1.0)) - Float64(sqrt(x) + Float64(sqrt(y) + sqrt(z)))));
                	else
                		tmp = Float64(1.0 + Float64(Float64(sqrt(Float64(1.0 + y)) + Float64(0.5 * sqrt(Float64(1.0 / z)))) - Float64(sqrt(x) + sqrt(y))));
                	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 <= 450000.0)
                		tmp = 2.0 + (sqrt((z + 1.0)) - (sqrt(x) + (sqrt(y) + sqrt(z))));
                	else
                		tmp = 1.0 + ((sqrt((1.0 + y)) + (0.5 * sqrt((1.0 / z)))) - (sqrt(x) + sqrt(y)));
                	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, 450000.0], N[(2.0 + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;z \leq 450000:\\
                \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if z < 4.5e5

                  1. Initial program 97.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.2%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+30.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified30.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around 0 23.5%

                    \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  9. Taylor expanded in y around 0 20.5%

                    \[\leadsto \color{blue}{\left(2 + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  10. Step-by-step derivation
                    1. associate--l+20.5%

                      \[\leadsto \color{blue}{2 + \left(\sqrt{1 + z} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  11. Simplified20.5%

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

                  if 4.5e5 < z

                  1. Initial program 87.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+87.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified87.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 4.3%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+19.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified19.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in z around inf 20.4%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right)\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  9. Step-by-step derivation
                    1. associate--l+30.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  10. Simplified30.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  11. Taylor expanded in x around 0 17.2%

                    \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right)\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  12. Step-by-step derivation
                    1. associate--l+31.4%

                      \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  13. Simplified31.4%

                    \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification25.7%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 450000:\\ \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;1 + \left(\left(\sqrt{1 + y} + 0.5 \cdot \sqrt{\frac{1}{z}}\right) - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \end{array} \]
                5. Add Preprocessing

                Alternative 13: 86.4% accurate, 2.0× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 2.2 \cdot 10^{-22}:\\ \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\ \mathbf{elif}\;y \leq 42000000:\\ \;\;\;\;1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{1 + x} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= y 2.2e-22)
                   (+ 2.0 (- (sqrt (+ z 1.0)) (+ (sqrt x) (+ (sqrt y) (sqrt z)))))
                   (if (<= y 42000000.0)
                     (+ 1.0 (- (sqrt (+ 1.0 y)) (+ (sqrt x) (sqrt y))))
                     (- (+ (sqrt (+ 1.0 x)) (* 0.5 (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 (y <= 2.2e-22) {
                		tmp = 2.0 + (sqrt((z + 1.0)) - (sqrt(x) + (sqrt(y) + sqrt(z))));
                	} else if (y <= 42000000.0) {
                		tmp = 1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y)));
                	} else {
                		tmp = (sqrt((1.0 + x)) + (0.5 * sqrt((1.0 / y)))) - sqrt(x);
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (y <= 2.2d-22) then
                        tmp = 2.0d0 + (sqrt((z + 1.0d0)) - (sqrt(x) + (sqrt(y) + sqrt(z))))
                    else if (y <= 42000000.0d0) then
                        tmp = 1.0d0 + (sqrt((1.0d0 + y)) - (sqrt(x) + sqrt(y)))
                    else
                        tmp = (sqrt((1.0d0 + x)) + (0.5d0 * 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 (y <= 2.2e-22) {
                		tmp = 2.0 + (Math.sqrt((z + 1.0)) - (Math.sqrt(x) + (Math.sqrt(y) + Math.sqrt(z))));
                	} else if (y <= 42000000.0) {
                		tmp = 1.0 + (Math.sqrt((1.0 + y)) - (Math.sqrt(x) + Math.sqrt(y)));
                	} else {
                		tmp = (Math.sqrt((1.0 + x)) + (0.5 * 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 y <= 2.2e-22:
                		tmp = 2.0 + (math.sqrt((z + 1.0)) - (math.sqrt(x) + (math.sqrt(y) + math.sqrt(z))))
                	elif y <= 42000000.0:
                		tmp = 1.0 + (math.sqrt((1.0 + y)) - (math.sqrt(x) + math.sqrt(y)))
                	else:
                		tmp = (math.sqrt((1.0 + x)) + (0.5 * 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 (y <= 2.2e-22)
                		tmp = Float64(2.0 + Float64(sqrt(Float64(z + 1.0)) - Float64(sqrt(x) + Float64(sqrt(y) + sqrt(z)))));
                	elseif (y <= 42000000.0)
                		tmp = Float64(1.0 + Float64(sqrt(Float64(1.0 + y)) - Float64(sqrt(x) + sqrt(y))));
                	else
                		tmp = Float64(Float64(sqrt(Float64(1.0 + x)) + Float64(0.5 * 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 (y <= 2.2e-22)
                		tmp = 2.0 + (sqrt((z + 1.0)) - (sqrt(x) + (sqrt(y) + sqrt(z))));
                	elseif (y <= 42000000.0)
                		tmp = 1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y)));
                	else
                		tmp = (sqrt((1.0 + x)) + (0.5 * 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[y, 2.2e-22], N[(2.0 + N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 42000000.0], N[(1.0 + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $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}\;y \leq 2.2 \cdot 10^{-22}:\\
                \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\
                
                \mathbf{elif}\;y \leq 42000000:\\
                \;\;\;\;1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;\left(\sqrt{1 + x} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 3 regimes
                2. if y < 2.2000000000000001e-22

                  1. Initial program 96.9%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+96.9%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative96.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified96.9%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 24.8%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+28.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified28.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around 0 20.7%

                    \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  9. Taylor expanded in y around 0 20.7%

                    \[\leadsto \color{blue}{\left(2 + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  10. Step-by-step derivation
                    1. associate--l+39.6%

                      \[\leadsto \color{blue}{2 + \left(\sqrt{1 + z} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  11. Simplified39.6%

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

                  if 2.2000000000000001e-22 < y < 4.2e7

                  1. Initial program 96.4%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+96.4%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg96.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg96.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative96.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative96.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative96.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified96.4%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 31.5%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+34.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified34.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in z around inf 22.8%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  9. Step-by-step derivation
                    1. associate--l+22.8%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  10. Simplified22.8%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  11. Taylor expanded in x around 0 20.6%

                    \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  12. Step-by-step derivation
                    1. associate--l+20.6%

                      \[\leadsto \color{blue}{1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  13. Simplified20.6%

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

                  if 4.2e7 < y

                  1. Initial program 87.4%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+87.4%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg87.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg87.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative87.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative87.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative87.4%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified87.4%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 5.4%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+20.8%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified20.8%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in z around inf 4.5%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  9. Step-by-step derivation
                    1. associate--l+18.9%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  10. Simplified18.9%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  11. Taylor expanded in y around inf 18.9%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}} \]
                3. Recombined 3 regimes into one program.
                4. Final simplification29.1%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 2.2 \cdot 10^{-22}:\\ \;\;\;\;2 + \left(\sqrt{z + 1} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\\ \mathbf{elif}\;y \leq 42000000:\\ \;\;\;\;1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{1 + x} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \]
                5. Add Preprocessing

                Alternative 14: 68.4% accurate, 2.6× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 1.0)
                   (+ 1.0 (- (sqrt (+ 1.0 y)) (+ (sqrt x) (sqrt y))))
                   (/ (+ (* -0.125 (sqrt (/ 1.0 x))) (* 0.5 (sqrt x))) x)))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 1.0) {
                		tmp = 1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y)));
                	} else {
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 1.0d0) then
                        tmp = 1.0d0 + (sqrt((1.0d0 + y)) - (sqrt(x) + sqrt(y)))
                    else
                        tmp = (((-0.125d0) * sqrt((1.0d0 / x))) + (0.5d0 * sqrt(x))) / 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 (x <= 1.0) {
                		tmp = 1.0 + (Math.sqrt((1.0 + y)) - (Math.sqrt(x) + Math.sqrt(y)));
                	} else {
                		tmp = ((-0.125 * Math.sqrt((1.0 / x))) + (0.5 * Math.sqrt(x))) / x;
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 1.0:
                		tmp = 1.0 + (math.sqrt((1.0 + y)) - (math.sqrt(x) + math.sqrt(y)))
                	else:
                		tmp = ((-0.125 * math.sqrt((1.0 / x))) + (0.5 * math.sqrt(x))) / x
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 1.0)
                		tmp = Float64(1.0 + Float64(sqrt(Float64(1.0 + y)) - Float64(sqrt(x) + sqrt(y))));
                	else
                		tmp = Float64(Float64(Float64(-0.125 * sqrt(Float64(1.0 / x))) + Float64(0.5 * sqrt(x))) / 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 (x <= 1.0)
                		tmp = 1.0 + (sqrt((1.0 + y)) - (sqrt(x) + sqrt(y)));
                	else
                		tmp = ((-0.125 * sqrt((1.0 / x))) + (0.5 * sqrt(x))) / 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[x, 1.0], N[(1.0 + N[(N[Sqrt[N[(1.0 + y), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(-0.125 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 1:\\
                \;\;\;\;1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)\\
                
                \mathbf{else}:\\
                \;\;\;\;\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 1

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.1%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+43.7%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified43.7%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in z around inf 24.0%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  9. Step-by-step derivation
                    1. associate--l+36.7%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  10. Simplified36.7%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  11. Taylor expanded in x around 0 24.0%

                    \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
                  12. Step-by-step derivation
                    1. associate--l+36.7%

                      \[\leadsto \color{blue}{1 + \left(\sqrt{1 + y} - \left(\sqrt{x} + \sqrt{y}\right)\right)} \]
                  13. Simplified36.7%

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

                  if 1 < x

                  1. Initial program 88.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+88.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified88.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{\frac{-0.125 \cdot \sqrt{\frac{1}{x}} + 0.5 \cdot \sqrt{x}}{x}} \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 15: 40.2% accurate, 3.9× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 70000000:\\ \;\;\;\;\sqrt{1 + x} - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 70000000.0) (- (sqrt (+ 1.0 x)) (sqrt x)) (* 0.5 (sqrt (/ 1.0 x)))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 70000000.0) {
                		tmp = sqrt((1.0 + x)) - sqrt(x);
                	} else {
                		tmp = 0.5 * sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 70000000.0d0) then
                        tmp = sqrt((1.0d0 + x)) - sqrt(x)
                    else
                        tmp = 0.5d0 * sqrt((1.0d0 / 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 (x <= 70000000.0) {
                		tmp = Math.sqrt((1.0 + x)) - Math.sqrt(x);
                	} else {
                		tmp = 0.5 * Math.sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 70000000.0:
                		tmp = math.sqrt((1.0 + x)) - math.sqrt(x)
                	else:
                		tmp = 0.5 * math.sqrt((1.0 / x))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 70000000.0)
                		tmp = Float64(sqrt(Float64(1.0 + x)) - sqrt(x));
                	else
                		tmp = Float64(0.5 * sqrt(Float64(1.0 / 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 (x <= 70000000.0)
                		tmp = sqrt((1.0 + x)) - sqrt(x);
                	else
                		tmp = 0.5 * sqrt((1.0 / 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[x, 70000000.0], N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 70000000:\\
                \;\;\;\;\sqrt{1 + x} - \sqrt{x}\\
                
                \mathbf{else}:\\
                \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 7e7

                  1. Initial program 97.6%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.6%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.6%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.6%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.6%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.6%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.6%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.6%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.8%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+44.1%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified44.1%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 25.2%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-125.2%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified25.2%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Step-by-step derivation
                    1. unsub-neg25.2%

                      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
                  12. Applied egg-rr25.2%

                    \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]

                  if 7e7 < x

                  1. Initial program 87.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+87.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative87.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified87.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 5.3%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+7.2%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified7.2%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.6%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.6%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.6%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.3%

                    \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}} \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 16: 39.8% accurate, 7.1× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(1 + x \cdot \left(0.5 + x \cdot -0.125\right)\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 1.0)
                   (- (+ 1.0 (* x (+ 0.5 (* x -0.125)))) (sqrt x))
                   (* 0.5 (sqrt (/ 1.0 x)))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 1.0) {
                		tmp = (1.0 + (x * (0.5 + (x * -0.125)))) - sqrt(x);
                	} else {
                		tmp = 0.5 * sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 1.0d0) then
                        tmp = (1.0d0 + (x * (0.5d0 + (x * (-0.125d0))))) - sqrt(x)
                    else
                        tmp = 0.5d0 * sqrt((1.0d0 / 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 (x <= 1.0) {
                		tmp = (1.0 + (x * (0.5 + (x * -0.125)))) - Math.sqrt(x);
                	} else {
                		tmp = 0.5 * Math.sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 1.0:
                		tmp = (1.0 + (x * (0.5 + (x * -0.125)))) - math.sqrt(x)
                	else:
                		tmp = 0.5 * math.sqrt((1.0 / x))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 1.0)
                		tmp = Float64(Float64(1.0 + Float64(x * Float64(0.5 + Float64(x * -0.125)))) - sqrt(x));
                	else
                		tmp = Float64(0.5 * sqrt(Float64(1.0 / 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 (x <= 1.0)
                		tmp = (1.0 + (x * (0.5 + (x * -0.125)))) - sqrt(x);
                	else
                		tmp = 0.5 * sqrt((1.0 / 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[x, 1.0], N[(N[(1.0 + N[(x * N[(0.5 + N[(x * -0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 1:\\
                \;\;\;\;\left(1 + x \cdot \left(0.5 + x \cdot -0.125\right)\right) - \sqrt{x}\\
                
                \mathbf{else}:\\
                \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 1

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.1%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+43.7%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified43.7%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 25.5%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-125.5%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified25.5%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around 0 25.5%

                    \[\leadsto \color{blue}{\left(1 + x \cdot \left(0.5 + -0.125 \cdot x\right)\right) - \sqrt{x}} \]

                  if 1 < x

                  1. Initial program 88.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+88.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified88.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification16.6%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(1 + x \cdot \left(0.5 + x \cdot -0.125\right)\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \]
                5. Add Preprocessing

                Alternative 17: 39.8% accurate, 7.3× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 8:\\ \;\;\;\;\left(1 + 0.5 \cdot x\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 8.0) (- (+ 1.0 (* 0.5 x)) (sqrt x)) (* 0.5 (sqrt (/ 1.0 x)))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 8.0) {
                		tmp = (1.0 + (0.5 * x)) - sqrt(x);
                	} else {
                		tmp = 0.5 * sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 8.0d0) then
                        tmp = (1.0d0 + (0.5d0 * x)) - sqrt(x)
                    else
                        tmp = 0.5d0 * sqrt((1.0d0 / 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 (x <= 8.0) {
                		tmp = (1.0 + (0.5 * x)) - Math.sqrt(x);
                	} else {
                		tmp = 0.5 * Math.sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 8.0:
                		tmp = (1.0 + (0.5 * x)) - math.sqrt(x)
                	else:
                		tmp = 0.5 * math.sqrt((1.0 / x))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 8.0)
                		tmp = Float64(Float64(1.0 + Float64(0.5 * x)) - sqrt(x));
                	else
                		tmp = Float64(0.5 * sqrt(Float64(1.0 / 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 (x <= 8.0)
                		tmp = (1.0 + (0.5 * x)) - sqrt(x);
                	else
                		tmp = 0.5 * sqrt((1.0 / 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[x, 8.0], N[(N[(1.0 + N[(0.5 * x), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 8:\\
                \;\;\;\;\left(1 + 0.5 \cdot x\right) - \sqrt{x}\\
                
                \mathbf{else}:\\
                \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 8

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.0%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+43.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified43.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 25.4%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-125.4%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified25.4%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around 0 25.5%

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

                  if 8 < x

                  1. Initial program 87.9%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+87.9%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg87.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg87.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative87.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative87.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative87.9%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified87.9%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.5%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.5%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}} \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 18: 39.6% accurate, 7.5× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 0.0205:\\ \;\;\;\;1 - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t)
                 :precision binary64
                 (if (<= x 0.0205) (- 1.0 (sqrt x)) (* 0.5 (sqrt (/ 1.0 x)))))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	double tmp;
                	if (x <= 0.0205) {
                		tmp = 1.0 - sqrt(x);
                	} else {
                		tmp = 0.5 * sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    real(8) :: tmp
                    if (x <= 0.0205d0) then
                        tmp = 1.0d0 - sqrt(x)
                    else
                        tmp = 0.5d0 * sqrt((1.0d0 / 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 (x <= 0.0205) {
                		tmp = 1.0 - Math.sqrt(x);
                	} else {
                		tmp = 0.5 * Math.sqrt((1.0 / x));
                	}
                	return tmp;
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	tmp = 0
                	if x <= 0.0205:
                		tmp = 1.0 - math.sqrt(x)
                	else:
                		tmp = 0.5 * math.sqrt((1.0 / x))
                	return tmp
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	tmp = 0.0
                	if (x <= 0.0205)
                		tmp = Float64(1.0 - sqrt(x));
                	else
                		tmp = Float64(0.5 * sqrt(Float64(1.0 / 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 (x <= 0.0205)
                		tmp = 1.0 - sqrt(x);
                	else
                		tmp = 0.5 * sqrt((1.0 / 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[x, 0.0205], N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                \begin{array}{l}
                \mathbf{if}\;x \leq 0.0205:\\
                \;\;\;\;1 - \sqrt{x}\\
                
                \mathbf{else}:\\
                \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if x < 0.0205000000000000009

                  1. Initial program 97.7%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+97.7%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative97.7%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified97.7%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 27.1%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+43.7%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified43.7%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 25.5%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-125.5%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified25.5%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around 0 25.5%

                    \[\leadsto \color{blue}{1 - \sqrt{x}} \]

                  if 0.0205000000000000009 < x

                  1. Initial program 88.0%

                    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                  2. Step-by-step derivation
                    1. associate-+l+88.0%

                      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                    2. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    3. sub-neg88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    4. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    5. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                    6. +-commutative88.0%

                      \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                  3. Simplified88.0%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                  4. Add Preprocessing
                  5. Taylor expanded in t around inf 6.6%

                    \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                  6. Step-by-step derivation
                    1. associate--l+8.6%

                      \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  7. Simplified8.6%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                  8. Taylor expanded in x around inf 3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                  9. Step-by-step derivation
                    1. neg-mul-13.9%

                      \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  10. Simplified3.9%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                  11. Taylor expanded in x around inf 8.5%

                    \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}} \]
                3. Recombined 2 regimes into one program.
                4. Add Preprocessing

                Alternative 19: 34.8% accurate, 8.0× speedup?

                \[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ 1 - \sqrt{x} \end{array} \]
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                (FPCore (x y z t) :precision binary64 (- 1.0 (sqrt x)))
                assert(x < y && y < z && z < t);
                double code(double x, double y, double z, double t) {
                	return 1.0 - sqrt(x);
                }
                
                NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    code = 1.0d0 - sqrt(x)
                end function
                
                assert x < y && y < z && z < t;
                public static double code(double x, double y, double z, double t) {
                	return 1.0 - Math.sqrt(x);
                }
                
                [x, y, z, t] = sort([x, y, z, t])
                def code(x, y, z, t):
                	return 1.0 - math.sqrt(x)
                
                x, y, z, t = sort([x, y, z, t])
                function code(x, y, z, t)
                	return Float64(1.0 - sqrt(x))
                end
                
                x, y, z, t = num2cell(sort([x, y, z, t])){:}
                function tmp = code(x, y, z, t)
                	tmp = 1.0 - 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[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
                
                \begin{array}{l}
                [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
                \\
                1 - \sqrt{x}
                \end{array}
                
                Derivation
                1. Initial program 92.6%

                  \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
                2. Step-by-step derivation
                  1. associate-+l+92.6%

                    \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
                  2. sub-neg92.6%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} + \left(-\sqrt{y}\right)\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  3. sub-neg92.6%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\left(\sqrt{y + 1} - \sqrt{y}\right)}\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  4. +-commutative92.6%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{\color{blue}{1 + y}} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  5. +-commutative92.6%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{\color{blue}{1 + z}} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
                  6. +-commutative92.6%

                    \[\leadsto \left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{\color{blue}{1 + t}} - \sqrt{t}\right)\right) \]
                3. Simplified92.6%

                  \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{1 + y} - \sqrt{y}\right)\right) + \left(\left(\sqrt{1 + z} - \sqrt{z}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)} \]
                4. Add Preprocessing
                5. Taylor expanded in t around inf 16.4%

                  \[\leadsto \color{blue}{\left(\sqrt{1 + x} + \left(\sqrt{1 + y} + \sqrt{1 + z}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)} \]
                6. Step-by-step derivation
                  1. associate--l+25.3%

                    \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                7. Simplified25.3%

                  \[\leadsto \color{blue}{\sqrt{1 + x} + \left(\left(\sqrt{1 + y} + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
                8. Taylor expanded in x around inf 14.2%

                  \[\leadsto \sqrt{1 + x} + \color{blue}{-1 \cdot \sqrt{x}} \]
                9. Step-by-step derivation
                  1. neg-mul-114.2%

                    \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                10. Simplified14.2%

                  \[\leadsto \sqrt{1 + x} + \color{blue}{\left(-\sqrt{x}\right)} \]
                11. Taylor expanded in x around 0 12.9%

                  \[\leadsto \color{blue}{1 - \sqrt{x}} \]
                12. Add Preprocessing

                Developer Target 1: 99.3% accurate, 1.0× speedup?

                \[\begin{array}{l} \\ \left(\left(\frac{1}{\sqrt{x + 1} + \sqrt{x}} + \frac{1}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \end{array} \]
                (FPCore (x y z t)
                 :precision binary64
                 (+
                  (+
                   (+
                    (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x)))
                    (/ 1.0 (+ (sqrt (+ y 1.0)) (sqrt y))))
                   (/ 1.0 (+ (sqrt (+ z 1.0)) (sqrt z))))
                  (- (sqrt (+ t 1.0)) (sqrt t))))
                double code(double x, double y, double z, double t) {
                	return (((1.0 / (sqrt((x + 1.0)) + sqrt(x))) + (1.0 / (sqrt((y + 1.0)) + sqrt(y)))) + (1.0 / (sqrt((z + 1.0)) + sqrt(z)))) + (sqrt((t + 1.0)) - sqrt(t));
                }
                
                real(8) function code(x, y, z, t)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8), intent (in) :: z
                    real(8), intent (in) :: t
                    code = (((1.0d0 / (sqrt((x + 1.0d0)) + sqrt(x))) + (1.0d0 / (sqrt((y + 1.0d0)) + sqrt(y)))) + (1.0d0 / (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 (((1.0 / (Math.sqrt((x + 1.0)) + Math.sqrt(x))) + (1.0 / (Math.sqrt((y + 1.0)) + Math.sqrt(y)))) + (1.0 / (Math.sqrt((z + 1.0)) + Math.sqrt(z)))) + (Math.sqrt((t + 1.0)) - Math.sqrt(t));
                }
                
                def code(x, y, z, t):
                	return (((1.0 / (math.sqrt((x + 1.0)) + math.sqrt(x))) + (1.0 / (math.sqrt((y + 1.0)) + math.sqrt(y)))) + (1.0 / (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(1.0 / Float64(sqrt(Float64(x + 1.0)) + sqrt(x))) + Float64(1.0 / Float64(sqrt(Float64(y + 1.0)) + sqrt(y)))) + Float64(1.0 / 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 = (((1.0 / (sqrt((x + 1.0)) + sqrt(x))) + (1.0 / (sqrt((y + 1.0)) + sqrt(y)))) + (1.0 / (sqrt((z + 1.0)) + sqrt(z)))) + (sqrt((t + 1.0)) - sqrt(t));
                end
                
                code[x_, y_, z_, t_] := N[(N[(N[(N[(1.0 / N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] + N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[N[(z + 1.0), $MachinePrecision]], $MachinePrecision] + N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(t + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \left(\left(\frac{1}{\sqrt{x + 1} + \sqrt{x}} + \frac{1}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
                \end{array}
                

                Reproduce

                ?
                herbie shell --seed 2024145 
                (FPCore (x y z t)
                  :name "Main:z from "
                  :precision binary64
                
                  :alt
                  (! :herbie-platform default (+ (+ (+ (/ 1 (+ (sqrt (+ x 1)) (sqrt x))) (/ 1 (+ (sqrt (+ y 1)) (sqrt y)))) (/ 1 (+ (sqrt (+ z 1)) (sqrt z)))) (- (sqrt (+ t 1)) (sqrt t))))
                
                  (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))