Main:z from

Percentage Accurate: 91.7% → 99.2%
Time: 37.5s
Alternatives: 24
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 24 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: 91.7% 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: 99.2% accurate, 0.9× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y + 1}\\ t_2 := \sqrt{1 + t} - \sqrt{t}\\ \mathbf{if}\;t\_1 - \sqrt{y} \leq 0:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + t\_2\\ \mathbf{else}:\\ \;\;\;\;t\_2 + \left(\left(\left(1 - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y} + t\_1}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right)\\ \end{array} \end{array} \]
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 (+ y 1.0))) (t_2 (- (sqrt (+ 1.0 t)) (sqrt t))))
   (if (<= (- t_1 (sqrt y)) 0.0)
     (+
      (+
       (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) (* 0.5 (sqrt (/ 1.0 y))))
       (* 0.5 (sqrt (/ 1.0 z))))
      t_2)
     (+
      t_2
      (+
       (+ (- 1.0 (sqrt x)) (/ (- (+ y 1.0) y) (+ (sqrt y) t_1)))
       (/ 1.0 (+ (sqrt z) (sqrt (+ 1.0 z)))))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((y + 1.0));
	double t_2 = sqrt((1.0 + t)) - sqrt(t);
	double tmp;
	if ((t_1 - sqrt(y)) <= 0.0) {
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + t_2;
	} else {
		tmp = t_2 + (((1.0 - sqrt(x)) + (((y + 1.0) - y) / (sqrt(y) + t_1))) + (1.0 / (sqrt(z) + sqrt((1.0 + 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) :: tmp
    t_1 = sqrt((y + 1.0d0))
    t_2 = sqrt((1.0d0 + t)) - sqrt(t)
    if ((t_1 - sqrt(y)) <= 0.0d0) then
        tmp = (((1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + (0.5d0 * sqrt((1.0d0 / y)))) + (0.5d0 * sqrt((1.0d0 / z)))) + t_2
    else
        tmp = t_2 + (((1.0d0 - sqrt(x)) + (((y + 1.0d0) - y) / (sqrt(y) + t_1))) + (1.0d0 / (sqrt(z) + sqrt((1.0d0 + 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((y + 1.0));
	double t_2 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
	double tmp;
	if ((t_1 - Math.sqrt(y)) <= 0.0) {
		tmp = (((1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + (0.5 * Math.sqrt((1.0 / y)))) + (0.5 * Math.sqrt((1.0 / z)))) + t_2;
	} else {
		tmp = t_2 + (((1.0 - Math.sqrt(x)) + (((y + 1.0) - y) / (Math.sqrt(y) + t_1))) + (1.0 / (Math.sqrt(z) + Math.sqrt((1.0 + z)))));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	t_1 = math.sqrt((y + 1.0))
	t_2 = math.sqrt((1.0 + t)) - math.sqrt(t)
	tmp = 0
	if (t_1 - math.sqrt(y)) <= 0.0:
		tmp = (((1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + (0.5 * math.sqrt((1.0 / y)))) + (0.5 * math.sqrt((1.0 / z)))) + t_2
	else:
		tmp = t_2 + (((1.0 - math.sqrt(x)) + (((y + 1.0) - y) / (math.sqrt(y) + t_1))) + (1.0 / (math.sqrt(z) + math.sqrt((1.0 + z)))))
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = sqrt(Float64(y + 1.0))
	t_2 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
	tmp = 0.0
	if (Float64(t_1 - sqrt(y)) <= 0.0)
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + Float64(0.5 * sqrt(Float64(1.0 / z)))) + t_2);
	else
		tmp = Float64(t_2 + Float64(Float64(Float64(1.0 - sqrt(x)) + Float64(Float64(Float64(y + 1.0) - y) / Float64(sqrt(y) + t_1))) + Float64(1.0 / Float64(sqrt(z) + sqrt(Float64(1.0 + 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((y + 1.0));
	t_2 = sqrt((1.0 + t)) - sqrt(t);
	tmp = 0.0;
	if ((t_1 - sqrt(y)) <= 0.0)
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + t_2;
	else
		tmp = t_2 + (((1.0 - sqrt(x)) + (((y + 1.0) - y) / (sqrt(y) + t_1))) + (1.0 / (sqrt(z) + sqrt((1.0 + 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[(y + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(t$95$1 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision], 0.0], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision], N[(t$95$2 + N[(N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(y + 1.0), $MachinePrecision] - y), $MachinePrecision] / N[(N[Sqrt[y], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(N[Sqrt[z], $MachinePrecision] + N[Sqrt[N[(1.0 + z), $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{y + 1}\\
t_2 := \sqrt{1 + t} - \sqrt{t}\\
\mathbf{if}\;t\_1 - \sqrt{y} \leq 0:\\
\;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + t\_2\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y)) < 0.0

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 46.4%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 51.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--51.8%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt43.5%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative43.5%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt51.8%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative51.8%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr51.8%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+53.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses53.4%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval53.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative53.4%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified53.4%

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

    if 0.0 < (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))

    1. Initial program 96.5%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. flip--96.7%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{\frac{\sqrt{z + 1} \cdot \sqrt{z + 1} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt79.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{\left(z + 1\right)} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative79.5%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{\left(1 + z\right)} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt96.7%

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

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

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

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

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

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{1}}{\sqrt{1 + z} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative97.2%

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

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{\frac{1}{\sqrt{z} + \sqrt{1 + z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. flip--97.4%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt97.7%

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

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(1 + y\right) - y}{\sqrt{\color{blue}{1 + y}} + \sqrt{y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      6. +-commutative98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(1 + y\right) - y}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Applied egg-rr98.2%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{y} + \sqrt{1 + y}}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    9. Taylor expanded in x around 0 57.4%

      \[\leadsto \left(\left(\color{blue}{\left(1 - \sqrt{x}\right)} + \frac{\left(1 + y\right) - y}{\sqrt{y} + \sqrt{1 + y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification55.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\sqrt{y + 1} - \sqrt{y} \leq 0:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(\left(\left(1 - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y} + \sqrt{y + 1}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 96.2% accurate, 0.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + t} - \sqrt{t}\\ t_2 := \sqrt{y + 1}\\ t_3 := \left(t\_2 - \sqrt{y}\right) + \left(\sqrt{1 + x} - \sqrt{x}\right)\\ \mathbf{if}\;t\_3 \leq 5 \cdot 10^{-7}:\\ \;\;\;\;t\_1 + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(0.5 \cdot \sqrt{\frac{1}{y}} + 0.5 \cdot \sqrt{\frac{1}{x}}\right)\right)\\ \mathbf{elif}\;t\_3 \leq 1.9999999995:\\ \;\;\;\;\left(1 - \sqrt{x}\right) + \mathsf{fma}\left(0.5, x, \frac{1}{\sqrt{y} + t\_2}\right)\\ \mathbf{else}:\\ \;\;\;\;2 + \left(\left(t\_1 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \end{array} \end{array} \]
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)))
        (t_2 (sqrt (+ y 1.0)))
        (t_3 (+ (- t_2 (sqrt y)) (- (sqrt (+ 1.0 x)) (sqrt x)))))
   (if (<= t_3 5e-7)
     (+
      t_1
      (+
       (* 0.5 (sqrt (/ 1.0 z)))
       (+ (* 0.5 (sqrt (/ 1.0 y))) (* 0.5 (sqrt (/ 1.0 x))))))
     (if (<= t_3 1.9999999995)
       (+ (- 1.0 (sqrt x)) (fma 0.5 x (/ 1.0 (+ (sqrt y) t_2))))
       (+
        2.0
        (- (+ t_1 (sqrt (+ 1.0 z))) (+ (sqrt z) (+ (sqrt y) (sqrt x)))))))))
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((y + 1.0));
	double t_3 = (t_2 - sqrt(y)) + (sqrt((1.0 + x)) - sqrt(x));
	double tmp;
	if (t_3 <= 5e-7) {
		tmp = t_1 + ((0.5 * sqrt((1.0 / z))) + ((0.5 * sqrt((1.0 / y))) + (0.5 * sqrt((1.0 / x)))));
	} else if (t_3 <= 1.9999999995) {
		tmp = (1.0 - sqrt(x)) + fma(0.5, x, (1.0 / (sqrt(y) + t_2)));
	} else {
		tmp = 2.0 + ((t_1 + sqrt((1.0 + z))) - (sqrt(z) + (sqrt(y) + sqrt(x))));
	}
	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(y + 1.0))
	t_3 = Float64(Float64(t_2 - sqrt(y)) + Float64(sqrt(Float64(1.0 + x)) - sqrt(x)))
	tmp = 0.0
	if (t_3 <= 5e-7)
		tmp = Float64(t_1 + Float64(Float64(0.5 * sqrt(Float64(1.0 / z))) + Float64(Float64(0.5 * sqrt(Float64(1.0 / y))) + Float64(0.5 * sqrt(Float64(1.0 / x))))));
	elseif (t_3 <= 1.9999999995)
		tmp = Float64(Float64(1.0 - sqrt(x)) + fma(0.5, x, Float64(1.0 / Float64(sqrt(y) + t_2))));
	else
		tmp = Float64(2.0 + Float64(Float64(t_1 + sqrt(Float64(1.0 + z))) - Float64(sqrt(z) + Float64(sqrt(y) + sqrt(x)))));
	end
	return tmp
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$3 = N[(N[(t$95$2 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$3, 5e-7], N[(t$95$1 + N[(N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$3, 1.9999999995], N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * x + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(2.0 + N[(N[(t$95$1 + N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[z], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $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{y + 1}\\
t_3 := \left(t\_2 - \sqrt{y}\right) + \left(\sqrt{1 + x} - \sqrt{x}\right)\\
\mathbf{if}\;t\_3 \leq 5 \cdot 10^{-7}:\\
\;\;\;\;t\_1 + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(0.5 \cdot \sqrt{\frac{1}{y}} + 0.5 \cdot \sqrt{\frac{1}{x}}\right)\right)\\

\mathbf{elif}\;t\_3 \leq 1.9999999995:\\
\;\;\;\;\left(1 - \sqrt{x}\right) + \mathsf{fma}\left(0.5, x, \frac{1}{\sqrt{y} + t\_2}\right)\\

\mathbf{else}:\\
\;\;\;\;2 + \left(\left(t\_1 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (+.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))) < 4.99999999999999977e-7

    1. Initial program 67.9%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 37.4%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 47.5%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Taylor expanded in x around inf 51.3%

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

    if 4.99999999999999977e-7 < (+.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))) < 1.9999999995

    1. Initial program 96.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+96.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-67.4%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-62.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative62.2%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative62.2%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+62.2%

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

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.4%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--24.4%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt14.6%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt24.6%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr24.6%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+25.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses25.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval25.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative25.1%

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

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around 0 25.2%

      \[\leadsto \color{blue}{\left(1 + \left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}} \]
    11. Step-by-step derivation
      1. +-commutative25.2%

        \[\leadsto \color{blue}{\left(\left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) + 1\right)} - \sqrt{x} \]
      2. associate--l+25.2%

        \[\leadsto \color{blue}{\left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) + \left(1 - \sqrt{x}\right)} \]
      3. fma-define25.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)} + \left(1 - \sqrt{x}\right) \]
    12. Simplified25.2%

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

    if 1.9999999995 < (+.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)))

    1. Initial program 98.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+98.1%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative98.1%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-98.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-98.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative98.2%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative98.2%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+98.2%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified78.7%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 78.7%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
    6. Taylor expanded in x around 0 26.8%

      \[\leadsto \color{blue}{\left(2 + \left(\sqrt{1 + t} + \sqrt{1 + z}\right)\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
    7. Step-by-step derivation
      1. associate--l+56.6%

        \[\leadsto \color{blue}{2 + \left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\right)} \]
      2. associate--r+45.8%

        \[\leadsto 2 + \color{blue}{\left(\left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
      3. +-commutative45.8%

        \[\leadsto 2 + \left(\left(\color{blue}{\left(\sqrt{1 + z} + \sqrt{1 + t}\right)} - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      4. metadata-eval45.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{\color{blue}{1 \cdot 1} + t}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      5. rem-square-sqrt45.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{1 \cdot 1 + \color{blue}{\sqrt{t} \cdot \sqrt{t}}}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      6. hypot-undefine45.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{t}\right)}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      7. associate-+r-78.4%

        \[\leadsto 2 + \left(\color{blue}{\left(\sqrt{1 + z} + \left(\mathsf{hypot}\left(1, \sqrt{t}\right) - \sqrt{t}\right)\right)} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      8. hypot-undefine78.4%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\color{blue}{\sqrt{1 \cdot 1 + \sqrt{t} \cdot \sqrt{t}}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      9. metadata-eval78.4%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{\color{blue}{1} + \sqrt{t} \cdot \sqrt{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      10. rem-square-sqrt78.4%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + \color{blue}{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      11. associate-+r+78.4%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) - \color{blue}{\left(\left(\sqrt{x} + \sqrt{y}\right) + \sqrt{z}\right)}\right) \]
    8. Simplified78.4%

      \[\leadsto \color{blue}{2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) - \left(\left(\sqrt{y} + \sqrt{x}\right) + \sqrt{z}\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification44.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{1 + x} - \sqrt{x}\right) \leq 5 \cdot 10^{-7}:\\ \;\;\;\;\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(0.5 \cdot \sqrt{\frac{1}{y}} + 0.5 \cdot \sqrt{\frac{1}{x}}\right)\right)\\ \mathbf{elif}\;\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{1 + x} - \sqrt{x}\right) \leq 1.9999999995:\\ \;\;\;\;\left(1 - \sqrt{x}\right) + \mathsf{fma}\left(0.5, x, \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right)\\ \mathbf{else}:\\ \;\;\;\;2 + \left(\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 97.4% accurate, 0.8× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y + 1}\\ t_2 := t\_1 - \sqrt{y}\\ t_3 := 0.5 \cdot \sqrt{\frac{1}{z}}\\ t_4 := \sqrt{1 + t} - \sqrt{t}\\ \mathbf{if}\;t\_2 \leq 0:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + t\_3\right) + t\_4\\ \mathbf{elif}\;t\_2 \leq 0.9999999995:\\ \;\;\;\;t\_4 + \left(t\_3 + \left(\left(1 - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y} + t\_1}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;2 + \left(\left(t\_4 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \end{array} \end{array} \]
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 1.0)))
        (t_2 (- t_1 (sqrt y)))
        (t_3 (* 0.5 (sqrt (/ 1.0 z))))
        (t_4 (- (sqrt (+ 1.0 t)) (sqrt t))))
   (if (<= t_2 0.0)
     (+
      (+
       (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) (* 0.5 (sqrt (/ 1.0 y))))
       t_3)
      t_4)
     (if (<= t_2 0.9999999995)
       (+
        t_4
        (+ t_3 (+ (- 1.0 (sqrt x)) (/ (- (+ y 1.0) y) (+ (sqrt y) t_1)))))
       (+
        2.0
        (- (+ t_4 (sqrt (+ 1.0 z))) (+ (sqrt z) (+ (sqrt y) (sqrt x)))))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((y + 1.0));
	double t_2 = t_1 - sqrt(y);
	double t_3 = 0.5 * sqrt((1.0 / z));
	double t_4 = sqrt((1.0 + t)) - sqrt(t);
	double tmp;
	if (t_2 <= 0.0) {
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + t_3) + t_4;
	} else if (t_2 <= 0.9999999995) {
		tmp = t_4 + (t_3 + ((1.0 - sqrt(x)) + (((y + 1.0) - y) / (sqrt(y) + t_1))));
	} else {
		tmp = 2.0 + ((t_4 + sqrt((1.0 + z))) - (sqrt(z) + (sqrt(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) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: t_4
    real(8) :: tmp
    t_1 = sqrt((y + 1.0d0))
    t_2 = t_1 - sqrt(y)
    t_3 = 0.5d0 * sqrt((1.0d0 / z))
    t_4 = sqrt((1.0d0 + t)) - sqrt(t)
    if (t_2 <= 0.0d0) then
        tmp = (((1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + (0.5d0 * sqrt((1.0d0 / y)))) + t_3) + t_4
    else if (t_2 <= 0.9999999995d0) then
        tmp = t_4 + (t_3 + ((1.0d0 - sqrt(x)) + (((y + 1.0d0) - y) / (sqrt(y) + t_1))))
    else
        tmp = 2.0d0 + ((t_4 + sqrt((1.0d0 + z))) - (sqrt(z) + (sqrt(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 t_1 = Math.sqrt((y + 1.0));
	double t_2 = t_1 - Math.sqrt(y);
	double t_3 = 0.5 * Math.sqrt((1.0 / z));
	double t_4 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
	double tmp;
	if (t_2 <= 0.0) {
		tmp = (((1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + (0.5 * Math.sqrt((1.0 / y)))) + t_3) + t_4;
	} else if (t_2 <= 0.9999999995) {
		tmp = t_4 + (t_3 + ((1.0 - Math.sqrt(x)) + (((y + 1.0) - y) / (Math.sqrt(y) + t_1))));
	} else {
		tmp = 2.0 + ((t_4 + Math.sqrt((1.0 + z))) - (Math.sqrt(z) + (Math.sqrt(y) + Math.sqrt(x))));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	t_1 = math.sqrt((y + 1.0))
	t_2 = t_1 - math.sqrt(y)
	t_3 = 0.5 * math.sqrt((1.0 / z))
	t_4 = math.sqrt((1.0 + t)) - math.sqrt(t)
	tmp = 0
	if t_2 <= 0.0:
		tmp = (((1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + (0.5 * math.sqrt((1.0 / y)))) + t_3) + t_4
	elif t_2 <= 0.9999999995:
		tmp = t_4 + (t_3 + ((1.0 - math.sqrt(x)) + (((y + 1.0) - y) / (math.sqrt(y) + t_1))))
	else:
		tmp = 2.0 + ((t_4 + math.sqrt((1.0 + z))) - (math.sqrt(z) + (math.sqrt(y) + math.sqrt(x))))
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = sqrt(Float64(y + 1.0))
	t_2 = Float64(t_1 - sqrt(y))
	t_3 = Float64(0.5 * sqrt(Float64(1.0 / z)))
	t_4 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
	tmp = 0.0
	if (t_2 <= 0.0)
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + t_3) + t_4);
	elseif (t_2 <= 0.9999999995)
		tmp = Float64(t_4 + Float64(t_3 + Float64(Float64(1.0 - sqrt(x)) + Float64(Float64(Float64(y + 1.0) - y) / Float64(sqrt(y) + t_1)))));
	else
		tmp = Float64(2.0 + Float64(Float64(t_4 + sqrt(Float64(1.0 + z))) - Float64(sqrt(z) + Float64(sqrt(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)
	t_1 = sqrt((y + 1.0));
	t_2 = t_1 - sqrt(y);
	t_3 = 0.5 * sqrt((1.0 / z));
	t_4 = sqrt((1.0 + t)) - sqrt(t);
	tmp = 0.0;
	if (t_2 <= 0.0)
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + t_3) + t_4;
	elseif (t_2 <= 0.9999999995)
		tmp = t_4 + (t_3 + ((1.0 - sqrt(x)) + (((y + 1.0) - y) / (sqrt(y) + t_1))));
	else
		tmp = 2.0 + ((t_4 + sqrt((1.0 + z))) - (sqrt(z) + (sqrt(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_] := Block[{t$95$1 = N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, 0.0], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$3), $MachinePrecision] + t$95$4), $MachinePrecision], If[LessEqual[t$95$2, 0.9999999995], N[(t$95$4 + N[(t$95$3 + N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(y + 1.0), $MachinePrecision] - y), $MachinePrecision] / N[(N[Sqrt[y], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(2.0 + N[(N[(t$95$4 + N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[z], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := \sqrt{y + 1}\\
t_2 := t\_1 - \sqrt{y}\\
t_3 := 0.5 \cdot \sqrt{\frac{1}{z}}\\
t_4 := \sqrt{1 + t} - \sqrt{t}\\
\mathbf{if}\;t\_2 \leq 0:\\
\;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + t\_3\right) + t\_4\\

\mathbf{elif}\;t\_2 \leq 0.9999999995:\\
\;\;\;\;t\_4 + \left(t\_3 + \left(\left(1 - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y} + t\_1}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;2 + \left(\left(t\_4 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y)) < 0.0

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 46.4%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 51.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--51.8%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt43.5%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative43.5%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt51.8%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative51.8%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr51.8%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+53.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses53.4%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval53.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative53.4%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified53.4%

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

    if 0.0 < (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y)) < 0.99999999949999996

    1. Initial program 88.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 48.0%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in x around 0 40.3%

      \[\leadsto \left(\left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--90.4%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{\frac{\sqrt{y + 1} \cdot \sqrt{y + 1} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt92.8%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(y + 1\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative92.8%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{y + 1} + \sqrt{y}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt97.5%

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

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

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{\left(1 + y\right) - y}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}}\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr42.7%

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

    if 0.99999999949999996 < (-.f64 (sqrt.f64 (+.f64 y #s(literal 1 binary64))) (sqrt.f64 y))

    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. +-commutative97.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-64.8%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-59.4%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative59.4%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative59.4%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+59.5%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 47.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
    6. Taylor expanded in x around 0 15.5%

      \[\leadsto \color{blue}{\left(2 + \left(\sqrt{1 + t} + \sqrt{1 + z}\right)\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
    7. Step-by-step derivation
      1. associate--l+38.1%

        \[\leadsto \color{blue}{2 + \left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\right)} \]
      2. associate--r+29.8%

        \[\leadsto 2 + \color{blue}{\left(\left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
      3. +-commutative29.8%

        \[\leadsto 2 + \left(\left(\color{blue}{\left(\sqrt{1 + z} + \sqrt{1 + t}\right)} - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      4. metadata-eval29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{\color{blue}{1 \cdot 1} + t}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      5. rem-square-sqrt29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{1 \cdot 1 + \color{blue}{\sqrt{t} \cdot \sqrt{t}}}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      6. hypot-undefine29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{t}\right)}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      7. associate-+r-48.3%

        \[\leadsto 2 + \left(\color{blue}{\left(\sqrt{1 + z} + \left(\mathsf{hypot}\left(1, \sqrt{t}\right) - \sqrt{t}\right)\right)} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      8. hypot-undefine48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\color{blue}{\sqrt{1 \cdot 1 + \sqrt{t} \cdot \sqrt{t}}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      9. metadata-eval48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{\color{blue}{1} + \sqrt{t} \cdot \sqrt{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      10. rem-square-sqrt48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + \color{blue}{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      11. associate-+r+48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) - \color{blue}{\left(\left(\sqrt{x} + \sqrt{y}\right) + \sqrt{z}\right)}\right) \]
    8. Simplified48.3%

      \[\leadsto \color{blue}{2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) - \left(\left(\sqrt{y} + \sqrt{x}\right) + \sqrt{z}\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification50.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\sqrt{y + 1} - \sqrt{y} \leq 0:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\\ \mathbf{elif}\;\sqrt{y + 1} - \sqrt{y} \leq 0.9999999995:\\ \;\;\;\;\left(\sqrt{1 + t} - \sqrt{t}\right) + \left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(\left(1 - \sqrt{x}\right) + \frac{\left(y + 1\right) - y}{\sqrt{y} + \sqrt{y + 1}}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;2 + \left(\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.1% accurate, 0.9× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{y + 1} - \sqrt{y}\\ t_2 := \sqrt{1 + t} - \sqrt{t}\\ \mathbf{if}\;t\_1 \leq 5 \cdot 10^{-5}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + t\_2\\ \mathbf{else}:\\ \;\;\;\;t\_2 + \left(\frac{1}{\sqrt{z} + \sqrt{1 + z}} + \left(t\_1 + \left(1 - \sqrt{x}\right)\right)\right)\\ \end{array} \end{array} \]
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 1.0)) (sqrt y)))
        (t_2 (- (sqrt (+ 1.0 t)) (sqrt t))))
   (if (<= t_1 5e-5)
     (+
      (+
       (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) (* 0.5 (sqrt (/ 1.0 y))))
       (* 0.5 (sqrt (/ 1.0 z))))
      t_2)
     (+
      t_2
      (+ (/ 1.0 (+ (sqrt z) (sqrt (+ 1.0 z)))) (+ t_1 (- 1.0 (sqrt x))))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((y + 1.0)) - sqrt(y);
	double t_2 = sqrt((1.0 + t)) - sqrt(t);
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + t_2;
	} else {
		tmp = t_2 + ((1.0 / (sqrt(z) + sqrt((1.0 + z)))) + (t_1 + (1.0 - 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) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = sqrt((y + 1.0d0)) - sqrt(y)
    t_2 = sqrt((1.0d0 + t)) - sqrt(t)
    if (t_1 <= 5d-5) then
        tmp = (((1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + (0.5d0 * sqrt((1.0d0 / y)))) + (0.5d0 * sqrt((1.0d0 / z)))) + t_2
    else
        tmp = t_2 + ((1.0d0 / (sqrt(z) + sqrt((1.0d0 + z)))) + (t_1 + (1.0d0 - 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 t_1 = Math.sqrt((y + 1.0)) - Math.sqrt(y);
	double t_2 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
	double tmp;
	if (t_1 <= 5e-5) {
		tmp = (((1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + (0.5 * Math.sqrt((1.0 / y)))) + (0.5 * Math.sqrt((1.0 / z)))) + t_2;
	} else {
		tmp = t_2 + ((1.0 / (Math.sqrt(z) + Math.sqrt((1.0 + z)))) + (t_1 + (1.0 - Math.sqrt(x))));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	t_1 = math.sqrt((y + 1.0)) - math.sqrt(y)
	t_2 = math.sqrt((1.0 + t)) - math.sqrt(t)
	tmp = 0
	if t_1 <= 5e-5:
		tmp = (((1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + (0.5 * math.sqrt((1.0 / y)))) + (0.5 * math.sqrt((1.0 / z)))) + t_2
	else:
		tmp = t_2 + ((1.0 / (math.sqrt(z) + math.sqrt((1.0 + z)))) + (t_1 + (1.0 - math.sqrt(x))))
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(sqrt(Float64(y + 1.0)) - sqrt(y))
	t_2 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
	tmp = 0.0
	if (t_1 <= 5e-5)
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + Float64(0.5 * sqrt(Float64(1.0 / z)))) + t_2);
	else
		tmp = Float64(t_2 + Float64(Float64(1.0 / Float64(sqrt(z) + sqrt(Float64(1.0 + z)))) + Float64(t_1 + Float64(1.0 - sqrt(x)))));
	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((y + 1.0)) - sqrt(y);
	t_2 = sqrt((1.0 + t)) - sqrt(t);
	tmp = 0.0;
	if (t_1 <= 5e-5)
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + t_2;
	else
		tmp = t_2 + ((1.0 / (sqrt(z) + sqrt((1.0 + z)))) + (t_1 + (1.0 - 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_] := Block[{t$95$1 = N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 5e-5], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision], N[(t$95$2 + N[(N[(1.0 / N[(N[Sqrt[z], $MachinePrecision] + N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 + N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := \sqrt{y + 1} - \sqrt{y}\\
t_2 := \sqrt{1 + t} - \sqrt{t}\\
\mathbf{if}\;t\_1 \leq 5 \cdot 10^{-5}:\\
\;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + t\_2\\

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


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

    1. Initial program 83.2%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 45.5%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 50.7%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--50.9%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt42.8%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative42.8%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt50.9%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative50.9%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr50.9%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+52.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses52.4%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval52.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative52.4%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified52.4%

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

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

    1. Initial program 97.5%

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

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{\frac{\sqrt{z + 1} \cdot \sqrt{z + 1} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt79.8%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{\left(z + 1\right)} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative79.8%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{\left(1 + z\right)} - \sqrt{z} \cdot \sqrt{z}}{\sqrt{z + 1} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt97.7%

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

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

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{\frac{\left(1 + z\right) - z}{\sqrt{1 + z} + \sqrt{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. associate-+r-98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{1 + \left(z - z\right)}}{\sqrt{1 + z} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{1 + \color{blue}{0}}{\sqrt{1 + z} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{\color{blue}{1}}{\sqrt{1 + z} + \sqrt{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative98.2%

        \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{1}{\color{blue}{\sqrt{z} + \sqrt{1 + z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Simplified98.2%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{\frac{1}{\sqrt{z} + \sqrt{1 + z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Taylor expanded in x around 0 57.9%

      \[\leadsto \left(\left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \frac{1}{\sqrt{z} + \sqrt{1 + z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification55.0%

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

Alternative 5: 96.4% accurate, 1.1× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + x}\\ t_2 := \sqrt{1 + t}\\ \mathbf{if}\;y \leq 1.1:\\ \;\;\;\;t\_1 + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(\sqrt{1 + z} + \frac{1}{\sqrt{t} + t\_2}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + t\_1} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(t\_2 - \sqrt{t}\right)\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (sqrt (+ 1.0 x))) (t_2 (sqrt (+ 1.0 t))))
   (if (<= y 1.1)
     (+
      t_1
      (+
       (- 1.0 (sqrt y))
       (-
        (- (+ (sqrt (+ 1.0 z)) (/ 1.0 (+ (sqrt t) t_2))) (sqrt x))
        (sqrt z))))
     (+
      (+
       (+ (/ 1.0 (+ (sqrt x) t_1)) (* 0.5 (sqrt (/ 1.0 y))))
       (* 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((1.0 + x));
	double t_2 = sqrt((1.0 + t));
	double tmp;
	if (y <= 1.1) {
		tmp = t_1 + ((1.0 - sqrt(y)) + (((sqrt((1.0 + z)) + (1.0 / (sqrt(t) + t_2))) - sqrt(x)) - sqrt(z)));
	} else {
		tmp = (((1.0 / (sqrt(x) + t_1)) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + (t_2 - sqrt(t));
	}
	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 + x))
    t_2 = sqrt((1.0d0 + t))
    if (y <= 1.1d0) then
        tmp = t_1 + ((1.0d0 - sqrt(y)) + (((sqrt((1.0d0 + z)) + (1.0d0 / (sqrt(t) + t_2))) - sqrt(x)) - sqrt(z)))
    else
        tmp = (((1.0d0 / (sqrt(x) + t_1)) + (0.5d0 * sqrt((1.0d0 / y)))) + (0.5d0 * sqrt((1.0d0 / z)))) + (t_2 - sqrt(t))
    end if
    code = tmp
end function
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double t_1 = Math.sqrt((1.0 + x));
	double t_2 = Math.sqrt((1.0 + t));
	double tmp;
	if (y <= 1.1) {
		tmp = t_1 + ((1.0 - Math.sqrt(y)) + (((Math.sqrt((1.0 + z)) + (1.0 / (Math.sqrt(t) + t_2))) - Math.sqrt(x)) - Math.sqrt(z)));
	} else {
		tmp = (((1.0 / (Math.sqrt(x) + t_1)) + (0.5 * Math.sqrt((1.0 / y)))) + (0.5 * Math.sqrt((1.0 / z)))) + (t_2 - Math.sqrt(t));
	}
	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 + t))
	tmp = 0
	if y <= 1.1:
		tmp = t_1 + ((1.0 - math.sqrt(y)) + (((math.sqrt((1.0 + z)) + (1.0 / (math.sqrt(t) + t_2))) - math.sqrt(x)) - math.sqrt(z)))
	else:
		tmp = (((1.0 / (math.sqrt(x) + t_1)) + (0.5 * math.sqrt((1.0 / y)))) + (0.5 * math.sqrt((1.0 / z)))) + (t_2 - math.sqrt(t))
	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 = sqrt(Float64(1.0 + t))
	tmp = 0.0
	if (y <= 1.1)
		tmp = Float64(t_1 + Float64(Float64(1.0 - sqrt(y)) + Float64(Float64(Float64(sqrt(Float64(1.0 + z)) + Float64(1.0 / Float64(sqrt(t) + t_2))) - sqrt(x)) - sqrt(z))));
	else
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + t_1)) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + Float64(0.5 * sqrt(Float64(1.0 / z)))) + Float64(t_2 - sqrt(t)));
	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 + t));
	tmp = 0.0;
	if (y <= 1.1)
		tmp = t_1 + ((1.0 - sqrt(y)) + (((sqrt((1.0 + z)) + (1.0 / (sqrt(t) + t_2))) - sqrt(x)) - sqrt(z)));
	else
		tmp = (((1.0 / (sqrt(x) + t_1)) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + (t_2 - sqrt(t));
	end
	tmp_2 = tmp;
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[y, 1.1], N[(t$95$1 + N[(N[(1.0 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision] + N[(1.0 / N[(N[Sqrt[t], $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 - N[Sqrt[t], $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 + t}\\
\mathbf{if}\;y \leq 1.1:\\
\;\;\;\;t\_1 + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(\sqrt{1 + z} + \frac{1}{\sqrt{t} + t\_2}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 1.1000000000000001

    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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 47.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
    6. Step-by-step derivation
      1. flip--47.9%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \color{blue}{\frac{\sqrt{1 + t} \cdot \sqrt{1 + t} - \sqrt{t} \cdot \sqrt{t}}{\sqrt{1 + t} + \sqrt{t}}}\right)\right) + \sqrt{z}\right)\right) \]
      2. add-sqr-sqrt36.8%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{\color{blue}{\left(1 + t\right)} - \sqrt{t} \cdot \sqrt{t}}{\sqrt{1 + t} + \sqrt{t}}\right)\right) + \sqrt{z}\right)\right) \]
      3. add-sqr-sqrt47.9%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{\left(1 + t\right) - \color{blue}{t}}{\sqrt{1 + t} + \sqrt{t}}\right)\right) + \sqrt{z}\right)\right) \]
    7. Applied egg-rr47.9%

      \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \color{blue}{\frac{\left(1 + t\right) - t}{\sqrt{1 + t} + \sqrt{t}}}\right)\right) + \sqrt{z}\right)\right) \]
    8. Step-by-step derivation
      1. associate--l+48.2%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{\color{blue}{1 + \left(t - t\right)}}{\sqrt{1 + t} + \sqrt{t}}\right)\right) + \sqrt{z}\right)\right) \]
      2. +-inverses48.2%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{1 + \color{blue}{0}}{\sqrt{1 + t} + \sqrt{t}}\right)\right) + \sqrt{z}\right)\right) \]
      3. metadata-eval48.2%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{\color{blue}{1}}{\sqrt{1 + t} + \sqrt{t}}\right)\right) + \sqrt{z}\right)\right) \]
      4. +-commutative48.2%

        \[\leadsto \sqrt{x + 1} + \left(\left(1 - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \frac{1}{\color{blue}{\sqrt{t} + \sqrt{1 + t}}}\right)\right) + \sqrt{z}\right)\right) \]
    9. Simplified48.2%

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

    if 1.1000000000000001 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 44.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 49.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--49.7%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt42.0%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative42.0%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt49.7%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative49.7%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr49.7%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+51.2%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses51.2%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval51.2%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative51.2%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified51.2%

      \[\leadsto \left(\left(\color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification49.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 1.1:\\ \;\;\;\;\sqrt{1 + x} + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(\sqrt{1 + z} + \frac{1}{\sqrt{t} + \sqrt{1 + t}}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 96.0% accurate, 1.1× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \sqrt{1 + t} - \sqrt{t}\\ t_2 := \sqrt{1 + x}\\ \mathbf{if}\;y \leq 0.86:\\ \;\;\;\;t\_2 + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(t\_1 + \sqrt{1 + z}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + t\_2} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + t\_1\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (- (sqrt (+ 1.0 t)) (sqrt t))) (t_2 (sqrt (+ 1.0 x))))
   (if (<= y 0.86)
     (+
      t_2
      (+ (- 1.0 (sqrt y)) (- (- (+ t_1 (sqrt (+ 1.0 z))) (sqrt x)) (sqrt z))))
     (+
      (+
       (+ (/ 1.0 (+ (sqrt x) t_2)) (* 0.5 (sqrt (/ 1.0 y))))
       (* 0.5 (sqrt (/ 1.0 z))))
      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);
	double t_2 = sqrt((1.0 + x));
	double tmp;
	if (y <= 0.86) {
		tmp = t_2 + ((1.0 - sqrt(y)) + (((t_1 + sqrt((1.0 + z))) - sqrt(x)) - sqrt(z)));
	} else {
		tmp = (((1.0 / (sqrt(x) + t_2)) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + 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) :: t_2
    real(8) :: tmp
    t_1 = sqrt((1.0d0 + t)) - sqrt(t)
    t_2 = sqrt((1.0d0 + x))
    if (y <= 0.86d0) then
        tmp = t_2 + ((1.0d0 - sqrt(y)) + (((t_1 + sqrt((1.0d0 + z))) - sqrt(x)) - sqrt(z)))
    else
        tmp = (((1.0d0 / (sqrt(x) + t_2)) + (0.5d0 * sqrt((1.0d0 / y)))) + (0.5d0 * sqrt((1.0d0 / z)))) + t_1
    end if
    code = tmp
end function
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double t_1 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
	double t_2 = Math.sqrt((1.0 + x));
	double tmp;
	if (y <= 0.86) {
		tmp = t_2 + ((1.0 - Math.sqrt(y)) + (((t_1 + Math.sqrt((1.0 + z))) - Math.sqrt(x)) - Math.sqrt(z)));
	} else {
		tmp = (((1.0 / (Math.sqrt(x) + t_2)) + (0.5 * Math.sqrt((1.0 / y)))) + (0.5 * Math.sqrt((1.0 / z)))) + 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)
	t_2 = math.sqrt((1.0 + x))
	tmp = 0
	if y <= 0.86:
		tmp = t_2 + ((1.0 - math.sqrt(y)) + (((t_1 + math.sqrt((1.0 + z))) - math.sqrt(x)) - math.sqrt(z)))
	else:
		tmp = (((1.0 / (math.sqrt(x) + t_2)) + (0.5 * math.sqrt((1.0 / y)))) + (0.5 * math.sqrt((1.0 / z)))) + t_1
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
	t_2 = sqrt(Float64(1.0 + x))
	tmp = 0.0
	if (y <= 0.86)
		tmp = Float64(t_2 + Float64(Float64(1.0 - sqrt(y)) + Float64(Float64(Float64(t_1 + sqrt(Float64(1.0 + z))) - sqrt(x)) - sqrt(z))));
	else
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + t_2)) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + Float64(0.5 * sqrt(Float64(1.0 / z)))) + t_1);
	end
	return tmp
end
x, y, z, t = num2cell(sort([x, y, z, t])){:}
function tmp_2 = code(x, y, z, t)
	t_1 = sqrt((1.0 + t)) - sqrt(t);
	t_2 = sqrt((1.0 + x));
	tmp = 0.0;
	if (y <= 0.86)
		tmp = t_2 + ((1.0 - sqrt(y)) + (((t_1 + sqrt((1.0 + z))) - sqrt(x)) - sqrt(z)));
	else
		tmp = (((1.0 / (sqrt(x) + t_2)) + (0.5 * sqrt((1.0 / y)))) + (0.5 * sqrt((1.0 / z)))) + t_1;
	end
	tmp_2 = tmp;
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[y, 0.86], N[(t$95$2 + N[(N[(1.0 - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(t$95$1 + N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] - N[Sqrt[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / z), $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 := \sqrt{1 + t} - \sqrt{t}\\
t_2 := \sqrt{1 + x}\\
\mathbf{if}\;y \leq 0.86:\\
\;\;\;\;t\_2 + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(t\_1 + \sqrt{1 + z}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 0.859999999999999987

    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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 47.9%

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

    if 0.859999999999999987 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 44.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 49.6%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--49.7%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt42.0%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative42.0%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt49.7%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative49.7%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr49.7%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+51.2%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses51.2%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval51.2%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative51.2%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified51.2%

      \[\leadsto \left(\left(\color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification49.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 0.86:\\ \;\;\;\;\sqrt{1 + x} + \left(\left(1 - \sqrt{y}\right) + \left(\left(\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \sqrt{1 + z}\right) - \sqrt{x}\right) - \sqrt{z}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 97.4% accurate, 1.3× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := 0.5 \cdot \sqrt{\frac{1}{z}}\\ t_2 := \sqrt{1 + t} - \sqrt{t}\\ \mathbf{if}\;y \leq 4.8 \cdot 10^{-19}:\\ \;\;\;\;2 + \left(\left(t\_2 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \mathbf{elif}\;y \leq 14000000:\\ \;\;\;\;\left(t\_1 + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(1 - \sqrt{x}\right)\right)\right) + 0.5 \cdot \sqrt{\frac{1}{t}}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + t\_1\right) + t\_2\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (* 0.5 (sqrt (/ 1.0 z)))) (t_2 (- (sqrt (+ 1.0 t)) (sqrt t))))
   (if (<= y 4.8e-19)
     (+ 2.0 (- (+ t_2 (sqrt (+ 1.0 z))) (+ (sqrt z) (+ (sqrt y) (sqrt x)))))
     (if (<= y 14000000.0)
       (+
        (+ t_1 (+ (- (sqrt (+ y 1.0)) (sqrt y)) (- 1.0 (sqrt x))))
        (* 0.5 (sqrt (/ 1.0 t))))
       (+
        (+
         (+ (/ 1.0 (+ (sqrt x) (sqrt (+ 1.0 x)))) (* 0.5 (sqrt (/ 1.0 y))))
         t_1)
        t_2)))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double t_1 = 0.5 * sqrt((1.0 / z));
	double t_2 = sqrt((1.0 + t)) - sqrt(t);
	double tmp;
	if (y <= 4.8e-19) {
		tmp = 2.0 + ((t_2 + sqrt((1.0 + z))) - (sqrt(z) + (sqrt(y) + sqrt(x))));
	} else if (y <= 14000000.0) {
		tmp = (t_1 + ((sqrt((y + 1.0)) - sqrt(y)) + (1.0 - sqrt(x)))) + (0.5 * sqrt((1.0 / t)));
	} else {
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + t_1) + 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 = 0.5d0 * sqrt((1.0d0 / z))
    t_2 = sqrt((1.0d0 + t)) - sqrt(t)
    if (y <= 4.8d-19) then
        tmp = 2.0d0 + ((t_2 + sqrt((1.0d0 + z))) - (sqrt(z) + (sqrt(y) + sqrt(x))))
    else if (y <= 14000000.0d0) then
        tmp = (t_1 + ((sqrt((y + 1.0d0)) - sqrt(y)) + (1.0d0 - sqrt(x)))) + (0.5d0 * sqrt((1.0d0 / t)))
    else
        tmp = (((1.0d0 / (sqrt(x) + sqrt((1.0d0 + x)))) + (0.5d0 * sqrt((1.0d0 / y)))) + t_1) + t_2
    end if
    code = tmp
end function
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double t_1 = 0.5 * Math.sqrt((1.0 / z));
	double t_2 = Math.sqrt((1.0 + t)) - Math.sqrt(t);
	double tmp;
	if (y <= 4.8e-19) {
		tmp = 2.0 + ((t_2 + Math.sqrt((1.0 + z))) - (Math.sqrt(z) + (Math.sqrt(y) + Math.sqrt(x))));
	} else if (y <= 14000000.0) {
		tmp = (t_1 + ((Math.sqrt((y + 1.0)) - Math.sqrt(y)) + (1.0 - Math.sqrt(x)))) + (0.5 * Math.sqrt((1.0 / t)));
	} else {
		tmp = (((1.0 / (Math.sqrt(x) + Math.sqrt((1.0 + x)))) + (0.5 * Math.sqrt((1.0 / y)))) + t_1) + t_2;
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	t_1 = 0.5 * math.sqrt((1.0 / z))
	t_2 = math.sqrt((1.0 + t)) - math.sqrt(t)
	tmp = 0
	if y <= 4.8e-19:
		tmp = 2.0 + ((t_2 + math.sqrt((1.0 + z))) - (math.sqrt(z) + (math.sqrt(y) + math.sqrt(x))))
	elif y <= 14000000.0:
		tmp = (t_1 + ((math.sqrt((y + 1.0)) - math.sqrt(y)) + (1.0 - math.sqrt(x)))) + (0.5 * math.sqrt((1.0 / t)))
	else:
		tmp = (((1.0 / (math.sqrt(x) + math.sqrt((1.0 + x)))) + (0.5 * math.sqrt((1.0 / y)))) + t_1) + t_2
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	t_1 = Float64(0.5 * sqrt(Float64(1.0 / z)))
	t_2 = Float64(sqrt(Float64(1.0 + t)) - sqrt(t))
	tmp = 0.0
	if (y <= 4.8e-19)
		tmp = Float64(2.0 + Float64(Float64(t_2 + sqrt(Float64(1.0 + z))) - Float64(sqrt(z) + Float64(sqrt(y) + sqrt(x)))));
	elseif (y <= 14000000.0)
		tmp = Float64(Float64(t_1 + Float64(Float64(sqrt(Float64(y + 1.0)) - sqrt(y)) + Float64(1.0 - sqrt(x)))) + Float64(0.5 * sqrt(Float64(1.0 / t))));
	else
		tmp = Float64(Float64(Float64(Float64(1.0 / Float64(sqrt(x) + sqrt(Float64(1.0 + x)))) + Float64(0.5 * sqrt(Float64(1.0 / y)))) + t_1) + t_2);
	end
	return tmp
end
x, y, z, t = num2cell(sort([x, y, z, t])){:}
function tmp_2 = code(x, y, z, t)
	t_1 = 0.5 * sqrt((1.0 / z));
	t_2 = sqrt((1.0 + t)) - sqrt(t);
	tmp = 0.0;
	if (y <= 4.8e-19)
		tmp = 2.0 + ((t_2 + sqrt((1.0 + z))) - (sqrt(z) + (sqrt(y) + sqrt(x))));
	elseif (y <= 14000000.0)
		tmp = (t_1 + ((sqrt((y + 1.0)) - sqrt(y)) + (1.0 - sqrt(x)))) + (0.5 * sqrt((1.0 / t)));
	else
		tmp = (((1.0 / (sqrt(x) + sqrt((1.0 + x)))) + (0.5 * sqrt((1.0 / y)))) + t_1) + t_2;
	end
	tmp_2 = tmp;
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(0.5 * N[Sqrt[N[(1.0 / z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Sqrt[N[(1.0 + t), $MachinePrecision]], $MachinePrecision] - N[Sqrt[t], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, 4.8e-19], N[(2.0 + N[(N[(t$95$2 + N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[z], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 14000000.0], N[(N[(t$95$1 + N[(N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision] + N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / t), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[Sqrt[N[(1.0 / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$1), $MachinePrecision] + t$95$2), $MachinePrecision]]]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
t_1 := 0.5 \cdot \sqrt{\frac{1}{z}}\\
t_2 := \sqrt{1 + t} - \sqrt{t}\\
\mathbf{if}\;y \leq 4.8 \cdot 10^{-19}:\\
\;\;\;\;2 + \left(\left(t\_2 + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\

\mathbf{elif}\;y \leq 14000000:\\
\;\;\;\;\left(t\_1 + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(1 - \sqrt{x}\right)\right)\right) + 0.5 \cdot \sqrt{\frac{1}{t}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 4.80000000000000046e-19

    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. +-commutative97.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-64.8%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-59.4%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative59.4%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative59.4%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+59.5%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 47.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
    6. Taylor expanded in x around 0 15.5%

      \[\leadsto \color{blue}{\left(2 + \left(\sqrt{1 + t} + \sqrt{1 + z}\right)\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
    7. Step-by-step derivation
      1. associate--l+38.1%

        \[\leadsto \color{blue}{2 + \left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \left(\sqrt{t} + \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\right)} \]
      2. associate--r+29.8%

        \[\leadsto 2 + \color{blue}{\left(\left(\left(\sqrt{1 + t} + \sqrt{1 + z}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
      3. +-commutative29.8%

        \[\leadsto 2 + \left(\left(\color{blue}{\left(\sqrt{1 + z} + \sqrt{1 + t}\right)} - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      4. metadata-eval29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{\color{blue}{1 \cdot 1} + t}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      5. rem-square-sqrt29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \sqrt{1 \cdot 1 + \color{blue}{\sqrt{t} \cdot \sqrt{t}}}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      6. hypot-undefine29.8%

        \[\leadsto 2 + \left(\left(\left(\sqrt{1 + z} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{t}\right)}\right) - \sqrt{t}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      7. associate-+r-48.3%

        \[\leadsto 2 + \left(\color{blue}{\left(\sqrt{1 + z} + \left(\mathsf{hypot}\left(1, \sqrt{t}\right) - \sqrt{t}\right)\right)} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      8. hypot-undefine48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\color{blue}{\sqrt{1 \cdot 1 + \sqrt{t} \cdot \sqrt{t}}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      9. metadata-eval48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{\color{blue}{1} + \sqrt{t} \cdot \sqrt{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      10. rem-square-sqrt48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + \color{blue}{t}} - \sqrt{t}\right)\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right) \]
      11. associate-+r+48.3%

        \[\leadsto 2 + \left(\left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right) - \color{blue}{\left(\left(\sqrt{x} + \sqrt{y}\right) + \sqrt{z}\right)}\right) \]
    8. Simplified48.3%

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

    if 4.80000000000000046e-19 < y < 1.4e7

    1. Initial program 96.3%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 60.8%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in x around 0 51.0%

      \[\leadsto \left(\left(\color{blue}{\left(1 - \sqrt{x}\right)} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Taylor expanded in t around inf 25.2%

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

    if 1.4e7 < y

    1. Initial program 83.2%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 45.5%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{z}}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    4. Taylor expanded in y around inf 50.7%

      \[\leadsto \left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \color{blue}{0.5 \cdot \sqrt{\frac{1}{y}}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    5. Step-by-step derivation
      1. flip--50.9%

        \[\leadsto \left(\left(\color{blue}{\frac{\sqrt{x + 1} \cdot \sqrt{x + 1} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. add-sqr-sqrt42.8%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(x + 1\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. +-commutative42.8%

        \[\leadsto \left(\left(\frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. add-sqr-sqrt50.9%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{x + 1} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      5. +-commutative50.9%

        \[\leadsto \left(\left(\frac{\left(1 + x\right) - x}{\sqrt{\color{blue}{1 + x}} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    6. Applied egg-rr50.9%

      \[\leadsto \left(\left(\color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    7. Step-by-step derivation
      1. associate--l+52.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      2. +-inverses52.4%

        \[\leadsto \left(\left(\frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      3. metadata-eval52.4%

        \[\leadsto \left(\left(\frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
      4. +-commutative52.4%

        \[\leadsto \left(\left(\frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    8. Simplified52.4%

      \[\leadsto \left(\left(\color{blue}{\frac{1}{\sqrt{x} + \sqrt{1 + x}}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  3. Recombined 3 regimes into one program.
  4. Final simplification49.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 4.8 \cdot 10^{-19}:\\ \;\;\;\;2 + \left(\left(\left(\sqrt{1 + t} - \sqrt{t}\right) + \sqrt{1 + z}\right) - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\\ \mathbf{elif}\;y \leq 14000000:\\ \;\;\;\;\left(0.5 \cdot \sqrt{\frac{1}{z}} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(1 - \sqrt{x}\right)\right)\right) + 0.5 \cdot \sqrt{\frac{1}{t}}\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\frac{1}{\sqrt{x} + \sqrt{1 + x}} + 0.5 \cdot \sqrt{\frac{1}{y}}\right) + 0.5 \cdot \sqrt{\frac{1}{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 90.7% accurate, 1.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 4.25 \cdot 10^{-19}:\\ \;\;\;\;\sqrt{1 + x} + \left(1 + \left(\sqrt{1 + z} - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\right)\\ \mathbf{elif}\;y \leq 8.5 \cdot 10^{+27}:\\ \;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (if (<= y 4.25e-19)
   (+
    (sqrt (+ 1.0 x))
    (+ 1.0 (- (sqrt (+ 1.0 z)) (+ (sqrt z) (+ (sqrt y) (sqrt x))))))
   (if (<= y 8.5e+27)
     (- (+ 1.0 (/ 1.0 (+ (sqrt y) (sqrt (+ y 1.0))))) (sqrt x))
     (/ 1.0 (+ (sqrt x) (hypot 1.0 (sqrt x)))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 4.25e-19) {
		tmp = sqrt((1.0 + x)) + (1.0 + (sqrt((1.0 + z)) - (sqrt(z) + (sqrt(y) + sqrt(x)))));
	} else if (y <= 8.5e+27) {
		tmp = (1.0 + (1.0 / (sqrt(y) + sqrt((y + 1.0))))) - sqrt(x);
	} else {
		tmp = 1.0 / (sqrt(x) + hypot(1.0, sqrt(x)));
	}
	return tmp;
}
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 4.25e-19) {
		tmp = Math.sqrt((1.0 + x)) + (1.0 + (Math.sqrt((1.0 + z)) - (Math.sqrt(z) + (Math.sqrt(y) + Math.sqrt(x)))));
	} else if (y <= 8.5e+27) {
		tmp = (1.0 + (1.0 / (Math.sqrt(y) + Math.sqrt((y + 1.0))))) - Math.sqrt(x);
	} else {
		tmp = 1.0 / (Math.sqrt(x) + Math.hypot(1.0, Math.sqrt(x)));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if y <= 4.25e-19:
		tmp = math.sqrt((1.0 + x)) + (1.0 + (math.sqrt((1.0 + z)) - (math.sqrt(z) + (math.sqrt(y) + math.sqrt(x)))))
	elif y <= 8.5e+27:
		tmp = (1.0 + (1.0 / (math.sqrt(y) + math.sqrt((y + 1.0))))) - math.sqrt(x)
	else:
		tmp = 1.0 / (math.sqrt(x) + math.hypot(1.0, 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 <= 4.25e-19)
		tmp = Float64(sqrt(Float64(1.0 + x)) + Float64(1.0 + Float64(sqrt(Float64(1.0 + z)) - Float64(sqrt(z) + Float64(sqrt(y) + sqrt(x))))));
	elseif (y <= 8.5e+27)
		tmp = Float64(Float64(1.0 + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(y + 1.0))))) - sqrt(x));
	else
		tmp = Float64(1.0 / Float64(sqrt(x) + hypot(1.0, 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 <= 4.25e-19)
		tmp = sqrt((1.0 + x)) + (1.0 + (sqrt((1.0 + z)) - (sqrt(z) + (sqrt(y) + sqrt(x)))));
	elseif (y <= 8.5e+27)
		tmp = (1.0 + (1.0 / (sqrt(y) + sqrt((y + 1.0))))) - sqrt(x);
	else
		tmp = 1.0 / (sqrt(x) + hypot(1.0, 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, 4.25e-19], N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(1.0 + N[(N[Sqrt[N[(1.0 + z), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[z], $MachinePrecision] + N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 8.5e+27], N[(N[(1.0 + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[1.0 ^ 2 + N[Sqrt[x], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq 4.25 \cdot 10^{-19}:\\
\;\;\;\;\sqrt{1 + x} + \left(1 + \left(\sqrt{1 + z} - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\right)\\

\mathbf{elif}\;y \leq 8.5 \cdot 10^{+27}:\\
\;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 4.25000000000000002e-19

    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. +-commutative97.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-64.8%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-59.4%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative59.4%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative59.4%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+59.5%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in y around 0 47.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
    6. Taylor expanded in t around inf 28.3%

      \[\leadsto \sqrt{x + 1} + \color{blue}{\left(\left(1 + \sqrt{1 + z}\right) - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)} \]
    7. Step-by-step derivation
      1. associate--l+37.5%

        \[\leadsto \sqrt{x + 1} + \color{blue}{\left(1 + \left(\sqrt{1 + z} - \left(\sqrt{x} + \left(\sqrt{y} + \sqrt{z}\right)\right)\right)\right)} \]
      2. associate-+r+37.5%

        \[\leadsto \sqrt{x + 1} + \left(1 + \left(\sqrt{1 + z} - \color{blue}{\left(\left(\sqrt{x} + \sqrt{y}\right) + \sqrt{z}\right)}\right)\right) \]
      3. +-commutative37.5%

        \[\leadsto \sqrt{x + 1} + \left(1 + \left(\sqrt{1 + z} - \left(\color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} + \sqrt{z}\right)\right)\right) \]
    8. Simplified37.5%

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

    if 4.25000000000000002e-19 < y < 8.5e27

    1. Initial program 75.9%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+75.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative75.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-68.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.2%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.2%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.2%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified48.4%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 26.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--26.1%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt26.2%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt27.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr27.1%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+29.8%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses29.8%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval29.8%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative29.8%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified29.8%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around 0 28.8%

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

    if 8.5e27 < y

    1. Initial program 85.9%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+85.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative85.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-85.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.8%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.8%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.8%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.8%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified43.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.9%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 21.9%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Step-by-step derivation
      1. flip--21.8%

        \[\leadsto \color{blue}{\frac{\sqrt{1 + x} \cdot \sqrt{1 + x} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. add-sqr-sqrt22.2%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. add-sqr-sqrt21.9%

        \[\leadsto \frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. div-sub21.9%

        \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    8. Applied egg-rr21.9%

      \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    9. Step-by-step derivation
      1. div-sub21.9%

        \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. associate--l+24.1%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. +-inverses24.1%

        \[\leadsto \frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. metadata-eval24.1%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} \]
      5. +-commutative24.1%

        \[\leadsto \frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} \]
      6. rem-square-sqrt24.1%

        \[\leadsto \frac{1}{\sqrt{x} + \sqrt{1 + \color{blue}{\sqrt{x} \cdot \sqrt{x}}}} \]
      7. hypot-1-def24.1%

        \[\leadsto \frac{1}{\sqrt{x} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
    10. Simplified24.1%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification30.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 4.25 \cdot 10^{-19}:\\ \;\;\;\;\sqrt{1 + x} + \left(1 + \left(\sqrt{1 + z} - \left(\sqrt{z} + \left(\sqrt{y} + \sqrt{x}\right)\right)\right)\right)\\ \mathbf{elif}\;y \leq 8.5 \cdot 10^{+27}:\\ \;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 72.0% accurate, 2.0× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\ \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(1 - \sqrt{x}\right) + \mathsf{fma}\left(0.5, x, t\_1\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\ \end{array} \end{array} \]
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 (/ 1.0 (+ (sqrt y) (sqrt (+ y 1.0))))))
   (if (<= x 1.0)
     (+ (- 1.0 (sqrt x)) (fma 0.5 x t_1))
     (+ (* 0.5 (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 = 1.0 / (sqrt(y) + sqrt((y + 1.0)));
	double tmp;
	if (x <= 1.0) {
		tmp = (1.0 - sqrt(x)) + fma(0.5, x, t_1);
	} else {
		tmp = (0.5 * 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(1.0 / Float64(sqrt(y) + sqrt(Float64(y + 1.0))))
	tmp = 0.0
	if (x <= 1.0)
		tmp = Float64(Float64(1.0 - sqrt(x)) + fma(0.5, x, t_1));
	else
		tmp = Float64(Float64(0.5 * sqrt(Float64(1.0 / x))) + t_1);
	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[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 1.0], N[(N[(1.0 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(0.5 * x + t$95$1), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[Sqrt[N[(1.0 / x), $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 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\
\mathbf{if}\;x \leq 1:\\
\;\;\;\;\left(1 - \sqrt{x}\right) + \mathsf{fma}\left(0.5, x, t\_1\right)\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1

    1. Initial program 97.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.1%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.1%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--37.7%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt28.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr37.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified38.4%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around 0 38.4%

      \[\leadsto \color{blue}{\left(1 + \left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)\right) - \sqrt{x}} \]
    11. Step-by-step derivation
      1. +-commutative38.4%

        \[\leadsto \color{blue}{\left(\left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) + 1\right)} - \sqrt{x} \]
      2. associate--l+38.4%

        \[\leadsto \color{blue}{\left(0.5 \cdot x + \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right) + \left(1 - \sqrt{x}\right)} \]
      3. fma-define38.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, \frac{1}{\sqrt{y} + \sqrt{1 + y}}\right)} + \left(1 - \sqrt{x}\right) \]
    12. Simplified38.4%

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

    if 1 < x

    1. Initial program 81.3%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-47.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-9.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative9.9%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative9.9%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+9.9%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified9.0%

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

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--4.3%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt4.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr4.3%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified4.3%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around inf 24.6%

      \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification32.2%

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

Alternative 10: 72.5% accurate, 2.0× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\ \mathbf{if}\;x \leq 49000000:\\ \;\;\;\;\sqrt{1 + x} + \left(t\_1 - \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\ \end{array} \end{array} \]
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 (/ 1.0 (+ (sqrt y) (sqrt (+ y 1.0))))))
   (if (<= x 49000000.0)
     (+ (sqrt (+ 1.0 x)) (- t_1 (sqrt x)))
     (+ (* 0.5 (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 = 1.0 / (sqrt(y) + sqrt((y + 1.0)));
	double tmp;
	if (x <= 49000000.0) {
		tmp = sqrt((1.0 + x)) + (t_1 - sqrt(x));
	} else {
		tmp = (0.5 * 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 = 1.0d0 / (sqrt(y) + sqrt((y + 1.0d0)))
    if (x <= 49000000.0d0) then
        tmp = sqrt((1.0d0 + x)) + (t_1 - sqrt(x))
    else
        tmp = (0.5d0 * 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 = 1.0 / (Math.sqrt(y) + Math.sqrt((y + 1.0)));
	double tmp;
	if (x <= 49000000.0) {
		tmp = Math.sqrt((1.0 + x)) + (t_1 - Math.sqrt(x));
	} else {
		tmp = (0.5 * 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 = 1.0 / (math.sqrt(y) + math.sqrt((y + 1.0)))
	tmp = 0
	if x <= 49000000.0:
		tmp = math.sqrt((1.0 + x)) + (t_1 - math.sqrt(x))
	else:
		tmp = (0.5 * 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(1.0 / Float64(sqrt(y) + sqrt(Float64(y + 1.0))))
	tmp = 0.0
	if (x <= 49000000.0)
		tmp = Float64(sqrt(Float64(1.0 + x)) + Float64(t_1 - sqrt(x)));
	else
		tmp = Float64(Float64(0.5 * 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 = 1.0 / (sqrt(y) + sqrt((y + 1.0)));
	tmp = 0.0;
	if (x <= 49000000.0)
		tmp = sqrt((1.0 + x)) + (t_1 - sqrt(x));
	else
		tmp = (0.5 * 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[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 49000000.0], N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[(t$95$1 - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[Sqrt[N[(1.0 / x), $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 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\
\mathbf{if}\;x \leq 49000000:\\
\;\;\;\;\sqrt{1 + x} + \left(t\_1 - \sqrt{x}\right)\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4.9e7

    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. +-commutative97.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.0%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.0%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.0%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.7%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.3%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--37.3%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt28.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt37.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr37.4%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified37.9%

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

    if 4.9e7 < x

    1. Initial program 81.0%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-45.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-7.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative7.7%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative7.7%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+7.7%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified6.7%

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

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--3.9%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt3.8%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt3.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr3.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+3.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses3.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval3.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative3.9%

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

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around inf 24.8%

      \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification32.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 49000000:\\ \;\;\;\;\sqrt{1 + x} + \left(\frac{1}{\sqrt{y} + \sqrt{y + 1}} - \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 71.7% accurate, 2.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} t_1 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\ \mathbf{if}\;x \leq 0.4:\\ \;\;\;\;\left(1 + t\_1\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\ \end{array} \end{array} \]
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 (/ 1.0 (+ (sqrt y) (sqrt (+ y 1.0))))))
   (if (<= x 0.4) (- (+ 1.0 t_1) (sqrt x)) (+ (* 0.5 (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 = 1.0 / (sqrt(y) + sqrt((y + 1.0)));
	double tmp;
	if (x <= 0.4) {
		tmp = (1.0 + t_1) - sqrt(x);
	} else {
		tmp = (0.5 * 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 = 1.0d0 / (sqrt(y) + sqrt((y + 1.0d0)))
    if (x <= 0.4d0) then
        tmp = (1.0d0 + t_1) - sqrt(x)
    else
        tmp = (0.5d0 * 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 = 1.0 / (Math.sqrt(y) + Math.sqrt((y + 1.0)));
	double tmp;
	if (x <= 0.4) {
		tmp = (1.0 + t_1) - Math.sqrt(x);
	} else {
		tmp = (0.5 * 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 = 1.0 / (math.sqrt(y) + math.sqrt((y + 1.0)))
	tmp = 0
	if x <= 0.4:
		tmp = (1.0 + t_1) - math.sqrt(x)
	else:
		tmp = (0.5 * 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(1.0 / Float64(sqrt(y) + sqrt(Float64(y + 1.0))))
	tmp = 0.0
	if (x <= 0.4)
		tmp = Float64(Float64(1.0 + t_1) - sqrt(x));
	else
		tmp = Float64(Float64(0.5 * 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 = 1.0 / (sqrt(y) + sqrt((y + 1.0)));
	tmp = 0.0;
	if (x <= 0.4)
		tmp = (1.0 + t_1) - sqrt(x);
	else
		tmp = (0.5 * 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[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, 0.4], N[(N[(1.0 + t$95$1), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[Sqrt[N[(1.0 / x), $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 := \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\
\mathbf{if}\;x \leq 0.4:\\
\;\;\;\;\left(1 + t\_1\right) - \sqrt{x}\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.40000000000000002

    1. Initial program 97.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.1%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.1%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--37.7%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt28.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt37.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr37.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative38.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified38.4%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around 0 37.7%

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

    if 0.40000000000000002 < x

    1. Initial program 81.3%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-47.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-9.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative9.9%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative9.9%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+9.9%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified9.0%

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

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Step-by-step derivation
      1. flip--4.3%

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt4.1%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr4.3%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative4.3%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified4.3%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around inf 24.6%

      \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}} + \frac{1}{\sqrt{y} + \sqrt{1 + y}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification31.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.4:\\ \;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}} + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 12: 71.7% accurate, 2.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{-15}:\\ \;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (if (<= x 1.55e-15)
   (- (+ 1.0 (/ 1.0 (+ (sqrt y) (sqrt (+ y 1.0))))) (sqrt x))
   (/ 1.0 (+ (sqrt x) (hypot 1.0 (sqrt x))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (x <= 1.55e-15) {
		tmp = (1.0 + (1.0 / (sqrt(y) + sqrt((y + 1.0))))) - sqrt(x);
	} else {
		tmp = 1.0 / (sqrt(x) + hypot(1.0, sqrt(x)));
	}
	return tmp;
}
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (x <= 1.55e-15) {
		tmp = (1.0 + (1.0 / (Math.sqrt(y) + Math.sqrt((y + 1.0))))) - Math.sqrt(x);
	} else {
		tmp = 1.0 / (Math.sqrt(x) + Math.hypot(1.0, Math.sqrt(x)));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if x <= 1.55e-15:
		tmp = (1.0 + (1.0 / (math.sqrt(y) + math.sqrt((y + 1.0))))) - math.sqrt(x)
	else:
		tmp = 1.0 / (math.sqrt(x) + math.hypot(1.0, math.sqrt(x)))
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	tmp = 0.0
	if (x <= 1.55e-15)
		tmp = Float64(Float64(1.0 + Float64(1.0 / Float64(sqrt(y) + sqrt(Float64(y + 1.0))))) - sqrt(x));
	else
		tmp = Float64(1.0 / Float64(sqrt(x) + hypot(1.0, 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 (x <= 1.55e-15)
		tmp = (1.0 + (1.0 / (sqrt(y) + sqrt((y + 1.0))))) - sqrt(x);
	else
		tmp = 1.0 / (sqrt(x) + hypot(1.0, 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[x, 1.55e-15], N[(N[(1.0 + N[(1.0 / N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[1.0 ^ 2 + N[Sqrt[x], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55 \cdot 10^{-15}:\\
\;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.5499999999999999e-15

    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. +-commutative97.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.0%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.0%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.0%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified76.1%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 36.8%

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

        \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\sqrt{1 + y} \cdot \sqrt{1 + y} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
      2. add-sqr-sqrt27.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{\left(1 + y\right)} - \sqrt{y} \cdot \sqrt{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. add-sqr-sqrt36.9%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\left(1 + y\right) - \color{blue}{y}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
    7. Applied egg-rr36.9%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{\left(1 + y\right) - y}{\sqrt{1 + y} + \sqrt{y}}} - \sqrt{x}\right) \]
    8. Step-by-step derivation
      1. associate--l+37.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1 + \left(y - y\right)}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      2. +-inverses37.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1 + \color{blue}{0}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      3. metadata-eval37.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{\color{blue}{1}}{\sqrt{1 + y} + \sqrt{y}} - \sqrt{x}\right) \]
      4. +-commutative37.4%

        \[\leadsto \sqrt{x + 1} + \left(\frac{1}{\color{blue}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    9. Simplified37.4%

      \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\frac{1}{\sqrt{y} + \sqrt{1 + y}}} - \sqrt{x}\right) \]
    10. Taylor expanded in x around 0 37.4%

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

    if 1.5499999999999999e-15 < x

    1. Initial program 82.2%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+82.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative82.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-49.8%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-14.4%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative14.4%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative14.4%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+14.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified11.4%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 7.0%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 6.5%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Step-by-step derivation
      1. flip--6.5%

        \[\leadsto \color{blue}{\frac{\sqrt{1 + x} \cdot \sqrt{1 + x} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. add-sqr-sqrt7.1%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. add-sqr-sqrt6.5%

        \[\leadsto \frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. div-sub6.5%

        \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    8. Applied egg-rr6.5%

      \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    9. Step-by-step derivation
      1. div-sub6.5%

        \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. associate--l+10.1%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. +-inverses10.1%

        \[\leadsto \frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. metadata-eval10.1%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} \]
      5. +-commutative10.1%

        \[\leadsto \frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} \]
      6. rem-square-sqrt10.1%

        \[\leadsto \frac{1}{\sqrt{x} + \sqrt{1 + \color{blue}{\sqrt{x} \cdot \sqrt{x}}}} \]
      7. hypot-1-def10.1%

        \[\leadsto \frac{1}{\sqrt{x} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
    10. Simplified10.1%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification24.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.55 \cdot 10^{-15}:\\ \;\;\;\;\left(1 + \frac{1}{\sqrt{y} + \sqrt{y + 1}}\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 13: 70.4% accurate, 2.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 3.1 \cdot 10^{-25}:\\ \;\;\;\;1 + \left(\sqrt{y + 1} - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (if (<= x 3.1e-25)
   (+ 1.0 (- (sqrt (+ y 1.0)) (+ (sqrt y) (sqrt x))))
   (/ 1.0 (+ (sqrt x) (hypot 1.0 (sqrt x))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (x <= 3.1e-25) {
		tmp = 1.0 + (sqrt((y + 1.0)) - (sqrt(y) + sqrt(x)));
	} else {
		tmp = 1.0 / (sqrt(x) + hypot(1.0, sqrt(x)));
	}
	return tmp;
}
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (x <= 3.1e-25) {
		tmp = 1.0 + (Math.sqrt((y + 1.0)) - (Math.sqrt(y) + Math.sqrt(x)));
	} else {
		tmp = 1.0 / (Math.sqrt(x) + Math.hypot(1.0, Math.sqrt(x)));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if x <= 3.1e-25:
		tmp = 1.0 + (math.sqrt((y + 1.0)) - (math.sqrt(y) + math.sqrt(x)))
	else:
		tmp = 1.0 / (math.sqrt(x) + math.hypot(1.0, math.sqrt(x)))
	return tmp
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	tmp = 0.0
	if (x <= 3.1e-25)
		tmp = Float64(1.0 + Float64(sqrt(Float64(y + 1.0)) - Float64(sqrt(y) + sqrt(x))));
	else
		tmp = Float64(1.0 / Float64(sqrt(x) + hypot(1.0, 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 (x <= 3.1e-25)
		tmp = 1.0 + (sqrt((y + 1.0)) - (sqrt(y) + sqrt(x)));
	else
		tmp = 1.0 / (sqrt(x) + hypot(1.0, 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[x, 3.1e-25], N[(1.0 + N[(N[Sqrt[N[(y + 1.0), $MachinePrecision]], $MachinePrecision] - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[1.0 ^ 2 + N[Sqrt[x], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
\mathbf{if}\;x \leq 3.1 \cdot 10^{-25}:\\
\;\;\;\;1 + \left(\sqrt{y + 1} - \left(\sqrt{y} + \sqrt{x}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.09999999999999995e-25

    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. +-commutative96.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-96.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-96.9%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+96.9%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified76.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.6%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 23.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative23.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+23.2%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-37.6%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-37.6%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+37.6%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval37.6%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt37.6%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine37.6%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified37.6%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Step-by-step derivation
      1. +-commutative37.6%

        \[\leadsto \color{blue}{\left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right) + 1} \]
      2. hypot-undefine37.6%

        \[\leadsto \left(\color{blue}{\sqrt{1 \cdot 1 + \sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) + 1 \]
      3. metadata-eval37.6%

        \[\leadsto \left(\sqrt{\color{blue}{1} + \sqrt{y} \cdot \sqrt{y}} - \left(\sqrt{y} + \sqrt{x}\right)\right) + 1 \]
      4. add-sqr-sqrt37.6%

        \[\leadsto \left(\sqrt{1 + \color{blue}{y}} - \left(\sqrt{y} + \sqrt{x}\right)\right) + 1 \]
      5. +-commutative37.6%

        \[\leadsto \left(\sqrt{1 + y} - \color{blue}{\left(\sqrt{x} + \sqrt{y}\right)}\right) + 1 \]
    10. Applied egg-rr37.6%

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

    if 3.09999999999999995e-25 < x

    1. Initial program 83.0%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.0%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-52.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-18.5%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative18.5%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative18.5%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+18.5%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified14.4%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 7.6%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 7.1%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Step-by-step derivation
      1. flip--7.0%

        \[\leadsto \color{blue}{\frac{\sqrt{1 + x} \cdot \sqrt{1 + x} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. add-sqr-sqrt7.6%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. add-sqr-sqrt7.1%

        \[\leadsto \frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. div-sub7.1%

        \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    8. Applied egg-rr7.1%

      \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    9. Step-by-step derivation
      1. div-sub7.1%

        \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. associate--l+10.5%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. +-inverses10.5%

        \[\leadsto \frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. metadata-eval10.5%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} \]
      5. +-commutative10.5%

        \[\leadsto \frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} \]
      6. rem-square-sqrt10.5%

        \[\leadsto \frac{1}{\sqrt{x} + \sqrt{1 + \color{blue}{\sqrt{x} \cdot \sqrt{x}}}} \]
      7. hypot-1-def10.5%

        \[\leadsto \frac{1}{\sqrt{x} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
    10. Simplified10.5%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification24.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 3.1 \cdot 10^{-25}:\\ \;\;\;\;1 + \left(\sqrt{y + 1} - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 14: 70.5% accurate, 2.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 3 \cdot 10^{+19}:\\ \;\;\;\;1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \sqrt{y}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\ \end{array} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t)
 :precision binary64
 (if (<= y 3e+19)
   (+ 1.0 (- (hypot 1.0 (sqrt y)) (sqrt y)))
   (/ 1.0 (+ (sqrt x) (hypot 1.0 (sqrt x))))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 3e+19) {
		tmp = 1.0 + (hypot(1.0, sqrt(y)) - sqrt(y));
	} else {
		tmp = 1.0 / (sqrt(x) + hypot(1.0, sqrt(x)));
	}
	return tmp;
}
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 3e+19) {
		tmp = 1.0 + (Math.hypot(1.0, Math.sqrt(y)) - Math.sqrt(y));
	} else {
		tmp = 1.0 / (Math.sqrt(x) + Math.hypot(1.0, Math.sqrt(x)));
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if y <= 3e+19:
		tmp = 1.0 + (math.hypot(1.0, math.sqrt(y)) - math.sqrt(y))
	else:
		tmp = 1.0 / (math.sqrt(x) + math.hypot(1.0, 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 <= 3e+19)
		tmp = Float64(1.0 + Float64(hypot(1.0, sqrt(y)) - sqrt(y)));
	else
		tmp = Float64(1.0 / Float64(sqrt(x) + hypot(1.0, 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 <= 3e+19)
		tmp = 1.0 + (hypot(1.0, sqrt(y)) - sqrt(y));
	else
		tmp = 1.0 / (sqrt(x) + hypot(1.0, 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, 3e+19], N[(1.0 + N[(N[Sqrt[1.0 ^ 2 + N[Sqrt[y], $MachinePrecision] ^ 2], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Sqrt[x], $MachinePrecision] + N[Sqrt[1.0 ^ 2 + N[Sqrt[x], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
\begin{array}{l}
\mathbf{if}\;y \leq 3 \cdot 10^{+19}:\\
\;\;\;\;1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \sqrt{y}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{x} + \mathsf{hypot}\left(1, \sqrt{x}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 3e19

    1. Initial program 96.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+96.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-66.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.4%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.4%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.4%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.5%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified48.6%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.4%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 23.0%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative23.0%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+23.0%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-23.0%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-23.0%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+23.0%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval23.0%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt23.0%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine23.0%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified23.0%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around inf 45.6%

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

    if 3e19 < y

    1. Initial program 83.9%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-83.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.1%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.1%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.1%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified42.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 21.2%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Step-by-step derivation
      1. flip--21.1%

        \[\leadsto \color{blue}{\frac{\sqrt{1 + x} \cdot \sqrt{1 + x} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. add-sqr-sqrt21.5%

        \[\leadsto \frac{\color{blue}{\left(1 + x\right)} - \sqrt{x} \cdot \sqrt{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. add-sqr-sqrt21.2%

        \[\leadsto \frac{\left(1 + x\right) - \color{blue}{x}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. div-sub21.2%

        \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    8. Applied egg-rr21.2%

      \[\leadsto \color{blue}{\frac{1 + x}{\sqrt{1 + x} + \sqrt{x}} - \frac{x}{\sqrt{1 + x} + \sqrt{x}}} \]
    9. Step-by-step derivation
      1. div-sub21.2%

        \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{\sqrt{1 + x} + \sqrt{x}}} \]
      2. associate--l+23.4%

        \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{\sqrt{1 + x} + \sqrt{x}} \]
      3. +-inverses23.4%

        \[\leadsto \frac{1 + \color{blue}{0}}{\sqrt{1 + x} + \sqrt{x}} \]
      4. metadata-eval23.4%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{1 + x} + \sqrt{x}} \]
      5. +-commutative23.4%

        \[\leadsto \frac{1}{\color{blue}{\sqrt{x} + \sqrt{1 + x}}} \]
      6. rem-square-sqrt23.4%

        \[\leadsto \frac{1}{\sqrt{x} + \sqrt{1 + \color{blue}{\sqrt{x} \cdot \sqrt{x}}}} \]
      7. hypot-1-def23.4%

        \[\leadsto \frac{1}{\sqrt{x} + \color{blue}{\mathsf{hypot}\left(1, \sqrt{x}\right)}} \]
    10. Simplified23.4%

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

Alternative 15: 69.4% accurate, 2.6× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 8.5:\\ \;\;\;\;1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \sqrt{y}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
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 8.5)
   (+ 1.0 (- (hypot 1.0 (sqrt y)) (sqrt y)))
   (* 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 <= 8.5) {
		tmp = 1.0 + (hypot(1.0, sqrt(y)) - sqrt(y));
	} else {
		tmp = 0.5 * sqrt((1.0 / x));
	}
	return tmp;
}
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (x <= 8.5) {
		tmp = 1.0 + (Math.hypot(1.0, Math.sqrt(y)) - Math.sqrt(y));
	} 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 <= 8.5:
		tmp = 1.0 + (math.hypot(1.0, math.sqrt(y)) - math.sqrt(y))
	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 <= 8.5)
		tmp = Float64(1.0 + Float64(hypot(1.0, sqrt(y)) - sqrt(y)));
	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 <= 8.5)
		tmp = 1.0 + (hypot(1.0, sqrt(y)) - sqrt(y));
	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, 8.5], N[(1.0 + N[(N[Sqrt[1.0 ^ 2 + N[Sqrt[y], $MachinePrecision] ^ 2], $MachinePrecision] - N[Sqrt[y], $MachinePrecision]), $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 8.5:\\
\;\;\;\;1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \sqrt{y}\right)\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 8.5

    1. Initial program 97.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.1%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.1%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.5%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.6%

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

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.3%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+21.8%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-36.9%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-36.9%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+36.4%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval36.4%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt36.4%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine36.4%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified36.4%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around inf 36.4%

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

    if 8.5 < x

    1. Initial program 81.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.1%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.1%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-46.7%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-9.2%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative9.2%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative9.2%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+9.2%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified8.2%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 4.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 3.7%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around inf 7.5%

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

Alternative 16: 64.9% accurate, 3.8× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 1:\\ \;\;\;\;1 + \left(\left(1 + y \cdot 0.5\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \end{array} \]
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 1.0)
   (+ 1.0 (- (+ 1.0 (* y 0.5)) (+ (sqrt y) (sqrt x))))
   (- (+ 1.0 (* 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 <= 1.0) {
		tmp = 1.0 + ((1.0 + (y * 0.5)) - (sqrt(y) + sqrt(x)));
	} else {
		tmp = (1.0 + (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 <= 1.0d0) then
        tmp = 1.0d0 + ((1.0d0 + (y * 0.5d0)) - (sqrt(y) + sqrt(x)))
    else
        tmp = (1.0d0 + (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 <= 1.0) {
		tmp = 1.0 + ((1.0 + (y * 0.5)) - (Math.sqrt(y) + Math.sqrt(x)));
	} else {
		tmp = (1.0 + (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 <= 1.0:
		tmp = 1.0 + ((1.0 + (y * 0.5)) - (math.sqrt(y) + math.sqrt(x)))
	else:
		tmp = (1.0 + (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 <= 1.0)
		tmp = Float64(1.0 + Float64(Float64(1.0 + Float64(y * 0.5)) - Float64(sqrt(y) + sqrt(x))));
	else
		tmp = Float64(Float64(1.0 + 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 <= 1.0)
		tmp = 1.0 + ((1.0 + (y * 0.5)) - (sqrt(y) + sqrt(x)));
	else
		tmp = (1.0 + (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, 1.0], N[(1.0 + N[(N[(1.0 + N[(y * 0.5), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + 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 1:\\
\;\;\;\;1 + \left(\left(1 + y \cdot 0.5\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 22.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+22.7%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-22.7%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-22.7%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+22.7%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval22.7%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt22.7%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine22.7%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified22.7%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around 0 22.7%

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

    if 1 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-82.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.6%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.6%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.6%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified44.0%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 5.1%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative5.1%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+4.2%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-19.8%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-19.8%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+27.3%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval27.3%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt27.3%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine27.3%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified27.3%

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

      \[\leadsto \color{blue}{\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification21.5%

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

Alternative 17: 64.9% accurate, 3.8× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 1:\\ \;\;\;\;\left(2 + y \cdot 0.5\right) - \left(\sqrt{y} + \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \end{array} \]
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 1.0)
   (- (+ 2.0 (* y 0.5)) (+ (sqrt y) (sqrt x)))
   (- (+ 1.0 (* 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 <= 1.0) {
		tmp = (2.0 + (y * 0.5)) - (sqrt(y) + sqrt(x));
	} else {
		tmp = (1.0 + (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 <= 1.0d0) then
        tmp = (2.0d0 + (y * 0.5d0)) - (sqrt(y) + sqrt(x))
    else
        tmp = (1.0d0 + (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 <= 1.0) {
		tmp = (2.0 + (y * 0.5)) - (Math.sqrt(y) + Math.sqrt(x));
	} else {
		tmp = (1.0 + (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 <= 1.0:
		tmp = (2.0 + (y * 0.5)) - (math.sqrt(y) + math.sqrt(x))
	else:
		tmp = (1.0 + (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 <= 1.0)
		tmp = Float64(Float64(2.0 + Float64(y * 0.5)) - Float64(sqrt(y) + sqrt(x)));
	else
		tmp = Float64(Float64(1.0 + 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 <= 1.0)
		tmp = (2.0 + (y * 0.5)) - (sqrt(y) + sqrt(x));
	else
		tmp = (1.0 + (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, 1.0], N[(N[(2.0 + N[(y * 0.5), $MachinePrecision]), $MachinePrecision] - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + 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 1:\\
\;\;\;\;\left(2 + y \cdot 0.5\right) - \left(\sqrt{y} + \sqrt{x}\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 22.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+22.7%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-22.7%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-22.7%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+22.7%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval22.7%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt22.7%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine22.7%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified22.7%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around 0 22.7%

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

    if 1 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-82.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.6%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.6%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.6%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified44.0%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 5.1%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative5.1%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+4.2%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-19.8%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-19.8%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+27.3%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval27.3%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt27.3%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine27.3%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified27.3%

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

      \[\leadsto \color{blue}{\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification21.5%

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

Alternative 18: 64.2% accurate, 3.8× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 0.37:\\ \;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \end{array} \]
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 0.37)
   (+ 1.0 (- 1.0 (+ (sqrt y) (sqrt x))))
   (- (+ 1.0 (* 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 <= 0.37) {
		tmp = 1.0 + (1.0 - (sqrt(y) + sqrt(x)));
	} else {
		tmp = (1.0 + (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 <= 0.37d0) then
        tmp = 1.0d0 + (1.0d0 - (sqrt(y) + sqrt(x)))
    else
        tmp = (1.0d0 + (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 <= 0.37) {
		tmp = 1.0 + (1.0 - (Math.sqrt(y) + Math.sqrt(x)));
	} else {
		tmp = (1.0 + (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 <= 0.37:
		tmp = 1.0 + (1.0 - (math.sqrt(y) + math.sqrt(x)))
	else:
		tmp = (1.0 + (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 <= 0.37)
		tmp = Float64(1.0 + Float64(1.0 - Float64(sqrt(y) + sqrt(x))));
	else
		tmp = Float64(Float64(1.0 + 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 <= 0.37)
		tmp = 1.0 + (1.0 - (sqrt(y) + sqrt(x)));
	else
		tmp = (1.0 + (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, 0.37], N[(1.0 + N[(1.0 - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + 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 0.37:\\
\;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 0.37

    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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 22.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+22.7%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-22.7%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-22.7%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+22.7%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval22.7%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt22.7%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine22.7%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified22.7%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around 0 22.7%

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

    if 0.37 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-82.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.6%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.6%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.6%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified44.0%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 5.1%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative5.1%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+4.2%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-19.8%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-19.8%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+27.3%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval27.3%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt27.3%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine27.3%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified27.3%

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

      \[\leadsto \color{blue}{\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification21.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 0.37:\\ \;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + 0.5 \cdot \sqrt{\frac{1}{y}}\right) - \sqrt{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 19: 63.1% accurate, 3.9× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 0.85:\\ \;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\ \end{array} \end{array} \]
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 0.85)
   (+ 1.0 (- 1.0 (+ (sqrt y) (sqrt x))))
   (- (+ 1.0 (* x 0.5)) (sqrt x))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 0.85) {
		tmp = 1.0 + (1.0 - (sqrt(y) + sqrt(x)));
	} else {
		tmp = (1.0 + (x * 0.5)) - 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 <= 0.85d0) then
        tmp = 1.0d0 + (1.0d0 - (sqrt(y) + sqrt(x)))
    else
        tmp = (1.0d0 + (x * 0.5d0)) - 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 <= 0.85) {
		tmp = 1.0 + (1.0 - (Math.sqrt(y) + Math.sqrt(x)));
	} else {
		tmp = (1.0 + (x * 0.5)) - Math.sqrt(x);
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if y <= 0.85:
		tmp = 1.0 + (1.0 - (math.sqrt(y) + math.sqrt(x)))
	else:
		tmp = (1.0 + (x * 0.5)) - 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 <= 0.85)
		tmp = Float64(1.0 + Float64(1.0 - Float64(sqrt(y) + sqrt(x))));
	else
		tmp = Float64(Float64(1.0 + Float64(x * 0.5)) - 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 <= 0.85)
		tmp = 1.0 + (1.0 - (sqrt(y) + sqrt(x)));
	else
		tmp = (1.0 + (x * 0.5)) - 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, 0.85], N[(1.0 + N[(1.0 - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(x * 0.5), $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 0.85:\\
\;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 0.849999999999999978

    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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 22.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+22.7%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-22.7%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-22.7%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+22.7%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval22.7%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt22.7%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine22.7%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified22.7%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around 0 22.7%

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

    if 0.849999999999999978 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-82.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.6%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.6%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.6%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified44.0%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 21.4%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around 0 22.0%

      \[\leadsto \color{blue}{\left(1 + 0.5 \cdot x\right) - \sqrt{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification22.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 0.85:\\ \;\;\;\;1 + \left(1 - \left(\sqrt{y} + \sqrt{x}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 20: 63.1% accurate, 3.9× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;y \leq 0.85:\\ \;\;\;\;2 - \left(\sqrt{y} + \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\ \end{array} \end{array} \]
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 0.85) (- 2.0 (+ (sqrt y) (sqrt x))) (- (+ 1.0 (* x 0.5)) (sqrt x))))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 0.85) {
		tmp = 2.0 - (sqrt(y) + sqrt(x));
	} else {
		tmp = (1.0 + (x * 0.5)) - 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 <= 0.85d0) then
        tmp = 2.0d0 - (sqrt(y) + sqrt(x))
    else
        tmp = (1.0d0 + (x * 0.5d0)) - 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 <= 0.85) {
		tmp = 2.0 - (Math.sqrt(y) + Math.sqrt(x));
	} else {
		tmp = (1.0 + (x * 0.5)) - Math.sqrt(x);
	}
	return tmp;
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	tmp = 0
	if y <= 0.85:
		tmp = 2.0 - (math.sqrt(y) + math.sqrt(x))
	else:
		tmp = (1.0 + (x * 0.5)) - 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 <= 0.85)
		tmp = Float64(2.0 - Float64(sqrt(y) + sqrt(x)));
	else
		tmp = Float64(Float64(1.0 + Float64(x * 0.5)) - 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 <= 0.85)
		tmp = 2.0 - (sqrt(y) + sqrt(x));
	else
		tmp = (1.0 + (x * 0.5)) - 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, 0.85], N[(2.0 - N[(N[Sqrt[y], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(x * 0.5), $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 0.85:\\
\;\;\;\;2 - \left(\sqrt{y} + \sqrt{x}\right)\\

\mathbf{else}:\\
\;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 0.849999999999999978

    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. +-commutative97.7%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-65.6%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-60.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative60.3%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative60.3%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+60.4%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified47.9%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 24.2%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in x around 0 22.7%

      \[\leadsto \color{blue}{\left(1 + \sqrt{1 + y}\right) - \left(\sqrt{x} + \sqrt{y}\right)} \]
    7. Step-by-step derivation
      1. +-commutative22.7%

        \[\leadsto \left(1 + \sqrt{1 + y}\right) - \color{blue}{\left(\sqrt{y} + \sqrt{x}\right)} \]
      2. associate--r+22.7%

        \[\leadsto \color{blue}{\left(\left(1 + \sqrt{1 + y}\right) - \sqrt{y}\right) - \sqrt{x}} \]
      3. associate-+r-22.7%

        \[\leadsto \color{blue}{\left(1 + \left(\sqrt{1 + y} - \sqrt{y}\right)\right)} - \sqrt{x} \]
      4. associate-+r-22.7%

        \[\leadsto \color{blue}{1 + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \sqrt{x}\right)} \]
      5. associate--r+22.7%

        \[\leadsto 1 + \color{blue}{\left(\sqrt{1 + y} - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
      6. metadata-eval22.7%

        \[\leadsto 1 + \left(\sqrt{\color{blue}{1 \cdot 1} + y} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      7. rem-square-sqrt22.7%

        \[\leadsto 1 + \left(\sqrt{1 \cdot 1 + \color{blue}{\sqrt{y} \cdot \sqrt{y}}} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
      8. hypot-undefine22.7%

        \[\leadsto 1 + \left(\color{blue}{\mathsf{hypot}\left(1, \sqrt{y}\right)} - \left(\sqrt{y} + \sqrt{x}\right)\right) \]
    8. Simplified22.7%

      \[\leadsto \color{blue}{1 + \left(\mathsf{hypot}\left(1, \sqrt{y}\right) - \left(\sqrt{y} + \sqrt{x}\right)\right)} \]
    9. Taylor expanded in y around 0 22.7%

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

    if 0.849999999999999978 < y

    1. Initial program 83.6%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative83.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-82.9%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-56.6%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative56.6%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative56.6%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+56.6%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified44.0%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 21.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 21.4%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around 0 22.0%

      \[\leadsto \color{blue}{\left(1 + 0.5 \cdot x\right) - \sqrt{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification22.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 0.85:\\ \;\;\;\;2 - \left(\sqrt{y} + \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 21: 40.0% accurate, 7.3× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\left(1 + x \cdot 0.5\right) - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
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)) (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)) - 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)) - 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)) - 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)) - 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 * 0.5)) - 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)) - 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 * 0.5), $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 0.5\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 97.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.1%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.1%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 27.6%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around 0 27.6%

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

    if 1 < x

    1. Initial program 81.3%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-47.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-9.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative9.9%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative9.9%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+9.9%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified9.0%

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

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 3.8%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around inf 7.6%

      \[\leadsto \color{blue}{0.5 \cdot \sqrt{\frac{1}{x}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification18.7%

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

Alternative 22: 39.8% accurate, 7.5× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ \begin{array}{l} \mathbf{if}\;x \leq 0.21:\\ \;\;\;\;1 - \sqrt{x}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{\frac{1}{x}}\\ \end{array} \end{array} \]
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 0.21) (- 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 <= 0.21) {
		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 <= 0.21d0) 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 <= 0.21) {
		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 <= 0.21:
		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 <= 0.21)
		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 <= 0.21)
		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, 0.21], 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 0.21:\\
\;\;\;\;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 < 0.209999999999999992

    1. Initial program 97.1%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+97.1%

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

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-97.1%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-97.1%

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

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

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+97.1%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified75.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 37.7%

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 27.6%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around 0 27.0%

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

    if 0.209999999999999992 < x

    1. Initial program 81.3%

      \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
    2. Step-by-step derivation
      1. associate-+l+81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
      2. +-commutative81.3%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      3. associate-+r-47.2%

        \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
      4. associate-+l-9.9%

        \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
      5. +-commutative9.9%

        \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
      6. +-commutative9.9%

        \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
      7. associate--l+9.9%

        \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
    3. Simplified9.0%

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

      \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
    6. Taylor expanded in y around inf 3.8%

      \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
    7. Taylor expanded in x around inf 7.6%

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

Alternative 23: 34.9% 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 90.1%

    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  2. Step-by-step derivation
    1. associate-+l+90.1%

      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
    2. +-commutative90.1%

      \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
    3. associate-+r-74.9%

      \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
    4. associate-+l-58.3%

      \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
    5. +-commutative58.3%

      \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
    6. +-commutative58.3%

      \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
    7. associate--l+58.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
  3. Simplified45.8%

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

    \[\leadsto \sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \color{blue}{\sqrt{x}}\right) \]
  6. Taylor expanded in y around inf 17.0%

    \[\leadsto \color{blue}{\sqrt{1 + x} - \sqrt{x}} \]
  7. Taylor expanded in x around 0 15.6%

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

Alternative 24: 1.7% accurate, 8.1× speedup?

\[\begin{array}{l} [x, y, z, t] = \mathsf{sort}([x, y, z, t])\\ \\ -\sqrt{y} \end{array} \]
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
(FPCore (x y z t) :precision binary64 (- (sqrt y)))
assert(x < y && y < z && z < t);
double code(double x, double y, double z, double t) {
	return -sqrt(y);
}
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 = -sqrt(y)
end function
assert x < y && y < z && z < t;
public static double code(double x, double y, double z, double t) {
	return -Math.sqrt(y);
}
[x, y, z, t] = sort([x, y, z, t])
def code(x, y, z, t):
	return -math.sqrt(y)
x, y, z, t = sort([x, y, z, t])
function code(x, y, z, t)
	return Float64(-sqrt(y))
end
x, y, z, t = num2cell(sort([x, y, z, t])){:}
function tmp = code(x, y, z, t)
	tmp = -sqrt(y);
end
NOTE: x, y, z, and t should be sorted in increasing order before calling this function.
code[x_, y_, z_, t_] := (-N[Sqrt[y], $MachinePrecision])
\begin{array}{l}
[x, y, z, t] = \mathsf{sort}([x, y, z, t])\\
\\
-\sqrt{y}
\end{array}
Derivation
  1. Initial program 90.1%

    \[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right) \]
  2. Step-by-step derivation
    1. associate-+l+90.1%

      \[\leadsto \color{blue}{\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)} \]
    2. +-commutative90.1%

      \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \left(\sqrt{x + 1} - \sqrt{x}\right)\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
    3. associate-+r-74.9%

      \[\leadsto \color{blue}{\left(\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \sqrt{x}\right)} + \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right) \]
    4. associate-+l-58.3%

      \[\leadsto \color{blue}{\left(\left(\sqrt{y + 1} - \sqrt{y}\right) + \sqrt{x + 1}\right) - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right)} \]
    5. +-commutative58.3%

      \[\leadsto \color{blue}{\left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right)} - \left(\sqrt{x} - \left(\left(\sqrt{z + 1} - \sqrt{z}\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\right)\right) \]
    6. +-commutative58.3%

      \[\leadsto \left(\sqrt{x + 1} + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) - \left(\sqrt{x} - \color{blue}{\left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)}\right) \]
    7. associate--l+58.3%

      \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{y + 1} - \sqrt{y}\right) - \left(\sqrt{x} - \left(\left(\sqrt{t + 1} - \sqrt{t}\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right)\right)\right)} \]
  3. Simplified45.8%

    \[\leadsto \color{blue}{\sqrt{x + 1} + \left(\left(\sqrt{1 + y} - \sqrt{y}\right) - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in y around 0 23.0%

    \[\leadsto \sqrt{x + 1} + \left(\color{blue}{\left(1 - \sqrt{y}\right)} - \left(\left(\sqrt{x} - \left(\sqrt{1 + z} + \left(\sqrt{1 + t} - \sqrt{t}\right)\right)\right) + \sqrt{z}\right)\right) \]
  6. Taylor expanded in y around inf 1.6%

    \[\leadsto \color{blue}{-1 \cdot \sqrt{y}} \]
  7. Step-by-step derivation
    1. neg-mul-11.6%

      \[\leadsto \color{blue}{-\sqrt{y}} \]
  8. Simplified1.6%

    \[\leadsto \color{blue}{-\sqrt{y}} \]
  9. Add Preprocessing

Developer target: 99.4% 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 2024096 
(FPCore (x y z t)
  :name "Main:z from "
  :precision binary64

  :alt
  (+ (+ (+ (/ 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)))

  (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))