Diagrams.TwoD.Apollonian:initialConfig from diagrams-contrib-1.3.0.5, A

Percentage Accurate: 68.8% → 99.9%
Time: 9.9s
Alternatives: 8
Speedup: 1.3×

Specification

?
\[\begin{array}{l} \\ \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))
double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
end function
public static double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
def code(x, y, z):
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
function code(x, y, z)
	return Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
end
function tmp = code(x, y, z)
	tmp = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
end
code[x_, y_, z_] := N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}
\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 8 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: 68.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))
double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
end function
public static double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
def code(x, y, z):
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
function code(x, y, z)
	return Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
end
function tmp = code(x, y, z)
	tmp = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
end
code[x_, y_, z_] := N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}
\end{array}

Alternative 1: 99.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ 0.5 \cdot \mathsf{fma}\left(x + z, \frac{x - z}{y}, y\right) \end{array} \]
(FPCore (x y z) :precision binary64 (* 0.5 (fma (+ x z) (/ (- x z) y) y)))
double code(double x, double y, double z) {
	return 0.5 * fma((x + z), ((x - z) / y), y);
}
function code(x, y, z)
	return Float64(0.5 * fma(Float64(x + z), Float64(Float64(x - z) / y), y))
end
code[x_, y_, z_] := N[(0.5 * N[(N[(x + z), $MachinePrecision] * N[(N[(x - z), $MachinePrecision] / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 \cdot \mathsf{fma}\left(x + z, \frac{x - z}{y}, y\right)
\end{array}
Derivation
  1. Initial program 74.5%

    \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{y}^{2} - {z}^{2}}{y} + \frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
  5. Final simplification99.9%

    \[\leadsto 0.5 \cdot \mathsf{fma}\left(x + z, \frac{x - z}{y}, y\right) \]
  6. Add Preprocessing

Alternative 2: 39.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(z \cdot \frac{z}{y}\right) \cdot -0.5\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq -1 \cdot 10^{-61}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* (* z (/ z y)) -0.5))
        (t_1 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
   (if (<= t_1 -1e-61)
     t_0
     (if (<= t_1 2e+112)
       (* y 0.5)
       (if (<= t_1 INFINITY) (* x (* 0.5 (/ x y))) t_0)))))
double code(double x, double y, double z) {
	double t_0 = (z * (z / y)) * -0.5;
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= -1e-61) {
		tmp = t_0;
	} else if (t_1 <= 2e+112) {
		tmp = y * 0.5;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = x * (0.5 * (x / y));
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double x, double y, double z) {
	double t_0 = (z * (z / y)) * -0.5;
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= -1e-61) {
		tmp = t_0;
	} else if (t_1 <= 2e+112) {
		tmp = y * 0.5;
	} else if (t_1 <= Double.POSITIVE_INFINITY) {
		tmp = x * (0.5 * (x / y));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = (z * (z / y)) * -0.5
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
	tmp = 0
	if t_1 <= -1e-61:
		tmp = t_0
	elif t_1 <= 2e+112:
		tmp = y * 0.5
	elif t_1 <= math.inf:
		tmp = x * (0.5 * (x / y))
	else:
		tmp = t_0
	return tmp
function code(x, y, z)
	t_0 = Float64(Float64(z * Float64(z / y)) * -0.5)
	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
	tmp = 0.0
	if (t_1 <= -1e-61)
		tmp = t_0;
	elseif (t_1 <= 2e+112)
		tmp = Float64(y * 0.5);
	elseif (t_1 <= Inf)
		tmp = Float64(x * Float64(0.5 * Float64(x / y)));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = (z * (z / y)) * -0.5;
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	tmp = 0.0;
	if (t_1 <= -1e-61)
		tmp = t_0;
	elseif (t_1 <= 2e+112)
		tmp = y * 0.5;
	elseif (t_1 <= Inf)
		tmp = x * (0.5 * (x / y));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(z * N[(z / y), $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -1e-61], t$95$0, If[LessEqual[t$95$1, 2e+112], N[(y * 0.5), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(x * N[(0.5 * N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(z \cdot \frac{z}{y}\right) \cdot -0.5\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq -1 \cdot 10^{-61}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+112}:\\
\;\;\;\;y \cdot 0.5\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 67.9%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}} \]
      2. clear-numN/A

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

        \[\leadsto \frac{1}{\frac{\color{blue}{y \cdot 2}}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
      4. associate-/l*N/A

        \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}}} \]
      5. associate-/r*N/A

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

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

        \[\leadsto \frac{\color{blue}{\frac{1}{y}}}{\frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
      8. lower-/.f6467.9

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

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

        \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\color{blue}{\left(x \cdot x + y \cdot y\right)} - z \cdot z}} \]
      11. associate--l+N/A

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

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

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

        \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\left(y \cdot y - \color{blue}{z \cdot z}\right) + x \cdot x}} \]
      15. difference-of-squaresN/A

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

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

        \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(\color{blue}{y + z}, y - z, x \cdot x\right)}} \]
      18. lower--.f6474.3

        \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(y + z, \color{blue}{y - z}, x \cdot x\right)}} \]
    4. Applied rewrites74.3%

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

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
      3. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{z}^{2}}{y}} \cdot \frac{-1}{2} \]
      4. unpow2N/A

        \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot \frac{-1}{2} \]
      5. lower-*.f6432.7

        \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot -0.5 \]
    7. Applied rewrites32.7%

      \[\leadsto \color{blue}{\frac{z \cdot z}{y} \cdot -0.5} \]
    8. Step-by-step derivation
      1. Applied rewrites35.0%

        \[\leadsto \left(\frac{z}{y} \cdot z\right) \cdot -0.5 \]

      if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 1.9999999999999999e112

      1. Initial program 84.6%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      2. Add Preprocessing
      3. Taylor expanded in y around inf

        \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
      4. Step-by-step derivation
        1. lower-*.f6461.4

          \[\leadsto \color{blue}{0.5 \cdot y} \]
      5. Applied rewrites61.4%

        \[\leadsto \color{blue}{0.5 \cdot y} \]

      if 1.9999999999999999e112 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

      1. Initial program 81.2%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}} \]
        2. clear-numN/A

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

          \[\leadsto \frac{1}{\frac{\color{blue}{y \cdot 2}}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
        4. associate-/l*N/A

          \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}}} \]
        5. associate-/r*N/A

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

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

          \[\leadsto \frac{\color{blue}{\frac{1}{y}}}{\frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
        8. lower-/.f6481.1

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

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

          \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\color{blue}{\left(x \cdot x + y \cdot y\right)} - z \cdot z}} \]
        11. associate--l+N/A

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

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

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

          \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\left(y \cdot y - \color{blue}{z \cdot z}\right) + x \cdot x}} \]
        15. difference-of-squaresN/A

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

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

          \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(\color{blue}{y + z}, y - z, x \cdot x\right)}} \]
        18. lower--.f6481.1

          \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(y + z, \color{blue}{y - z}, x \cdot x\right)}} \]
      4. Applied rewrites81.1%

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

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
      6. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
        2. lower-*.f64N/A

          \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
        3. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{{z}^{2}}{y}} \cdot \frac{-1}{2} \]
        4. unpow2N/A

          \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot \frac{-1}{2} \]
        5. lower-*.f6442.8

          \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot -0.5 \]
      7. Applied rewrites42.8%

        \[\leadsto \color{blue}{\frac{z \cdot z}{y} \cdot -0.5} \]
      8. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
      9. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{\frac{{x}^{2}}{y} \cdot \frac{1}{2}} \]
        2. unpow2N/A

          \[\leadsto \frac{\color{blue}{x \cdot x}}{y} \cdot \frac{1}{2} \]
        3. associate-/l*N/A

          \[\leadsto \color{blue}{\left(x \cdot \frac{x}{y}\right)} \cdot \frac{1}{2} \]
        4. associate-*r*N/A

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

          \[\leadsto x \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{x}{y}\right)} \]
        6. lower-*.f64N/A

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

          \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
        8. lower-*.f64N/A

          \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
        9. lower-/.f6438.8

          \[\leadsto x \cdot \left(\color{blue}{\frac{x}{y}} \cdot 0.5\right) \]
      10. Applied rewrites38.8%

        \[\leadsto \color{blue}{x \cdot \left(\frac{x}{y} \cdot 0.5\right)} \]
    9. Recombined 3 regimes into one program.
    10. Final simplification39.0%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\left(z \cdot \frac{z}{y}\right) \cdot -0.5\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(z \cdot \frac{z}{y}\right) \cdot -0.5\\ \end{array} \]
    11. Add Preprocessing

    Alternative 3: 68.0% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.5 \cdot \mathsf{fma}\left(-z, \frac{z}{y}, y\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq -1 \cdot 10^{-61}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (* 0.5 (fma (- z) (/ z y) y)))
            (t_1 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
       (if (<= t_1 -1e-61)
         t_0
         (if (<= t_1 INFINITY) (* 0.5 (fma x (/ x y) y)) t_0))))
    double code(double x, double y, double z) {
    	double t_0 = 0.5 * fma(-z, (z / y), y);
    	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= -1e-61) {
    		tmp = t_0;
    	} else if (t_1 <= ((double) INFINITY)) {
    		tmp = 0.5 * fma(x, (x / y), y);
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    function code(x, y, z)
    	t_0 = Float64(0.5 * fma(Float64(-z), Float64(z / y), y))
    	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
    	tmp = 0.0
    	if (t_1 <= -1e-61)
    		tmp = t_0;
    	elseif (t_1 <= Inf)
    		tmp = Float64(0.5 * fma(x, Float64(x / y), y));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[(0.5 * N[((-z) * N[(z / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -1e-61], t$95$0, If[LessEqual[t$95$1, Infinity], N[(0.5 * N[(x * N[(x / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision], t$95$0]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := 0.5 \cdot \mathsf{fma}\left(-z, \frac{z}{y}, y\right)\\
    t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
    \mathbf{if}\;t\_1 \leq -1 \cdot 10^{-61}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;t\_1 \leq \infty:\\
    \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

      1. Initial program 67.9%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{y}^{2} - {z}^{2}}{y}} \]
      4. Step-by-step derivation
        1. div-subN/A

          \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{{y}^{2}}{y} - \frac{{z}^{2}}{y}\right)} \]
        2. unpow2N/A

          \[\leadsto \frac{1}{2} \cdot \left(\frac{\color{blue}{y \cdot y}}{y} - \frac{{z}^{2}}{y}\right) \]
        3. associate-/l*N/A

          \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{y \cdot \frac{y}{y}} - \frac{{z}^{2}}{y}\right) \]
        4. *-inversesN/A

          \[\leadsto \frac{1}{2} \cdot \left(y \cdot \color{blue}{1} - \frac{{z}^{2}}{y}\right) \]
        5. *-rgt-identityN/A

          \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{y} - \frac{{z}^{2}}{y}\right) \]
        6. lower-*.f64N/A

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(y - \frac{{z}^{2}}{y}\right)} \]
        7. lower--.f64N/A

          \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(y - \frac{{z}^{2}}{y}\right)} \]
        8. lower-/.f64N/A

          \[\leadsto \frac{1}{2} \cdot \left(y - \color{blue}{\frac{{z}^{2}}{y}}\right) \]
        9. unpow2N/A

          \[\leadsto \frac{1}{2} \cdot \left(y - \frac{\color{blue}{z \cdot z}}{y}\right) \]
        10. lower-*.f6457.2

          \[\leadsto 0.5 \cdot \left(y - \frac{\color{blue}{z \cdot z}}{y}\right) \]
      5. Applied rewrites57.2%

        \[\leadsto \color{blue}{0.5 \cdot \left(y - \frac{z \cdot z}{y}\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites64.4%

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

        if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

        1. Initial program 81.9%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Taylor expanded in z around 0

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2} + {y}^{2}}{y}} \]
        4. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} + {x}^{2}}}{y} \]
          2. *-rgt-identityN/A

            \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot 1} + {x}^{2}}{y} \]
          3. *-lft-identityN/A

            \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{1 \cdot {x}^{2}}}{y} \]
          4. *-inversesN/A

            \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{\frac{{y}^{2}}{{y}^{2}}} \cdot {x}^{2}}{y} \]
          5. associate-*l/N/A

            \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{\frac{{y}^{2} \cdot {x}^{2}}{{y}^{2}}}}{y} \]
          6. associate-*r/N/A

            \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{{y}^{2} \cdot \frac{{x}^{2}}{{y}^{2}}}}{y} \]
          7. distribute-lft-inN/A

            \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)}}{y} \]
          8. associate-*l/N/A

            \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{{y}^{2}}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right)} \]
          9. unpow2N/A

            \[\leadsto \frac{1}{2} \cdot \left(\frac{\color{blue}{y \cdot y}}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
          10. associate-/l*N/A

            \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(y \cdot \frac{y}{y}\right)} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
          11. *-inversesN/A

            \[\leadsto \frac{1}{2} \cdot \left(\left(y \cdot \color{blue}{1}\right) \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
          12. *-rgt-identityN/A

            \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
          13. distribute-lft-inN/A

            \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(y \cdot 1 + y \cdot \frac{{x}^{2}}{{y}^{2}}\right)} \]
          14. *-rgt-identityN/A

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

            \[\leadsto \frac{1}{2} \cdot \left(y + \color{blue}{\frac{{x}^{2}}{{y}^{2}} \cdot y}\right) \]
          16. associate-/r/N/A

            \[\leadsto \frac{1}{2} \cdot \left(y + \color{blue}{\frac{{x}^{2}}{\frac{{y}^{2}}{y}}}\right) \]
          17. unpow2N/A

            \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\frac{\color{blue}{y \cdot y}}{y}}\right) \]
          18. associate-/l*N/A

            \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y \cdot \frac{y}{y}}}\right) \]
          19. *-inversesN/A

            \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{y \cdot \color{blue}{1}}\right) \]
          20. *-rgt-identityN/A

            \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y}}\right) \]
        5. Applied rewrites64.2%

          \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
      7. Recombined 2 regimes into one program.
      8. Add Preprocessing

      Alternative 4: 36.4% accurate, 0.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_0 \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\ \end{array} \end{array} \]
      (FPCore (x y z)
       :precision binary64
       (let* ((t_0 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
         (if (<= t_0 -1e-61)
           (/ (* (* z z) -0.5) y)
           (if (<= t_0 2e+112) (* y 0.5) (* x (* 0.5 (/ x y)))))))
      double code(double x, double y, double z) {
      	double t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	double tmp;
      	if (t_0 <= -1e-61) {
      		tmp = ((z * z) * -0.5) / y;
      	} else if (t_0 <= 2e+112) {
      		tmp = y * 0.5;
      	} else {
      		tmp = x * (0.5 * (x / y));
      	}
      	return tmp;
      }
      
      real(8) function code(x, y, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          real(8) :: t_0
          real(8) :: tmp
          t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
          if (t_0 <= (-1d-61)) then
              tmp = ((z * z) * (-0.5d0)) / y
          else if (t_0 <= 2d+112) then
              tmp = y * 0.5d0
          else
              tmp = x * (0.5d0 * (x / y))
          end if
          code = tmp
      end function
      
      public static double code(double x, double y, double z) {
      	double t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	double tmp;
      	if (t_0 <= -1e-61) {
      		tmp = ((z * z) * -0.5) / y;
      	} else if (t_0 <= 2e+112) {
      		tmp = y * 0.5;
      	} else {
      		tmp = x * (0.5 * (x / y));
      	}
      	return tmp;
      }
      
      def code(x, y, z):
      	t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
      	tmp = 0
      	if t_0 <= -1e-61:
      		tmp = ((z * z) * -0.5) / y
      	elif t_0 <= 2e+112:
      		tmp = y * 0.5
      	else:
      		tmp = x * (0.5 * (x / y))
      	return tmp
      
      function code(x, y, z)
      	t_0 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
      	tmp = 0.0
      	if (t_0 <= -1e-61)
      		tmp = Float64(Float64(Float64(z * z) * -0.5) / y);
      	elseif (t_0 <= 2e+112)
      		tmp = Float64(y * 0.5);
      	else
      		tmp = Float64(x * Float64(0.5 * Float64(x / y)));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y, z)
      	t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	tmp = 0.0;
      	if (t_0 <= -1e-61)
      		tmp = ((z * z) * -0.5) / y;
      	elseif (t_0 <= 2e+112)
      		tmp = y * 0.5;
      	else
      		tmp = x * (0.5 * (x / y));
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -1e-61], N[(N[(N[(z * z), $MachinePrecision] * -0.5), $MachinePrecision] / y), $MachinePrecision], If[LessEqual[t$95$0, 2e+112], N[(y * 0.5), $MachinePrecision], N[(x * N[(0.5 * N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
      \mathbf{if}\;t\_0 \leq -1 \cdot 10^{-61}:\\
      \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\
      
      \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+112}:\\
      \;\;\;\;y \cdot 0.5\\
      
      \mathbf{else}:\\
      \;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61

        1. Initial program 83.1%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Taylor expanded in z around inf

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
        4. Step-by-step derivation
          1. associate-*r/N/A

            \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot {z}^{2}}{y}} \]
          2. metadata-evalN/A

            \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
          3. associate-*r*N/A

            \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot \left(-1 \cdot {z}^{2}\right)}}{y} \]
          4. mul-1-negN/A

            \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(\mathsf{neg}\left({z}^{2}\right)\right)}}{y} \]
          5. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
          6. mul-1-negN/A

            \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
          7. associate-*r*N/A

            \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right) \cdot {z}^{2}}}{y} \]
          8. metadata-evalN/A

            \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
          9. *-commutativeN/A

            \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
          10. lower-*.f64N/A

            \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
          11. unpow2N/A

            \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
          12. lower-*.f6431.7

            \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
        5. Applied rewrites31.7%

          \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]

        if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 1.9999999999999999e112

        1. Initial program 84.6%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
        4. Step-by-step derivation
          1. lower-*.f6461.4

            \[\leadsto \color{blue}{0.5 \cdot y} \]
        5. Applied rewrites61.4%

          \[\leadsto \color{blue}{0.5 \cdot y} \]

        if 1.9999999999999999e112 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

        1. Initial program 64.3%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}} \]
          2. clear-numN/A

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

            \[\leadsto \frac{1}{\frac{\color{blue}{y \cdot 2}}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
          4. associate-/l*N/A

            \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}}} \]
          5. associate-/r*N/A

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

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

            \[\leadsto \frac{\color{blue}{\frac{1}{y}}}{\frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
          8. lower-/.f6464.4

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\color{blue}{\left(x \cdot x + y \cdot y\right)} - z \cdot z}} \]
          11. associate--l+N/A

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

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\left(y \cdot y - \color{blue}{z \cdot z}\right) + x \cdot x}} \]
          15. difference-of-squaresN/A

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(\color{blue}{y + z}, y - z, x \cdot x\right)}} \]
          18. lower--.f6471.6

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(y + z, \color{blue}{y - z}, x \cdot x\right)}} \]
        4. Applied rewrites71.6%

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

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
        6. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
          2. lower-*.f64N/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
          3. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y}} \cdot \frac{-1}{2} \]
          4. unpow2N/A

            \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot \frac{-1}{2} \]
          5. lower-*.f6441.5

            \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot -0.5 \]
        7. Applied rewrites41.5%

          \[\leadsto \color{blue}{\frac{z \cdot z}{y} \cdot -0.5} \]
        8. Taylor expanded in x around inf

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
        9. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{\frac{{x}^{2}}{y} \cdot \frac{1}{2}} \]
          2. unpow2N/A

            \[\leadsto \frac{\color{blue}{x \cdot x}}{y} \cdot \frac{1}{2} \]
          3. associate-/l*N/A

            \[\leadsto \color{blue}{\left(x \cdot \frac{x}{y}\right)} \cdot \frac{1}{2} \]
          4. associate-*r*N/A

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

            \[\leadsto x \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{x}{y}\right)} \]
          6. lower-*.f64N/A

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

            \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
          8. lower-*.f64N/A

            \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
          9. lower-/.f6435.9

            \[\leadsto x \cdot \left(\color{blue}{\frac{x}{y}} \cdot 0.5\right) \]
        10. Applied rewrites35.9%

          \[\leadsto \color{blue}{x \cdot \left(\frac{x}{y} \cdot 0.5\right)} \]
      3. Recombined 3 regimes into one program.
      4. Final simplification36.6%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(0.5 \cdot \frac{x}{y}\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 5: 36.4% accurate, 0.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_0 \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\ \end{array} \end{array} \]
      (FPCore (x y z)
       :precision binary64
       (let* ((t_0 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
         (if (<= t_0 -1e-61)
           (/ (* (* z z) -0.5) y)
           (if (<= t_0 2e+112) (* y 0.5) (* x (* x (/ 0.5 y)))))))
      double code(double x, double y, double z) {
      	double t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	double tmp;
      	if (t_0 <= -1e-61) {
      		tmp = ((z * z) * -0.5) / y;
      	} else if (t_0 <= 2e+112) {
      		tmp = y * 0.5;
      	} else {
      		tmp = x * (x * (0.5 / y));
      	}
      	return tmp;
      }
      
      real(8) function code(x, y, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          real(8) :: t_0
          real(8) :: tmp
          t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
          if (t_0 <= (-1d-61)) then
              tmp = ((z * z) * (-0.5d0)) / y
          else if (t_0 <= 2d+112) then
              tmp = y * 0.5d0
          else
              tmp = x * (x * (0.5d0 / y))
          end if
          code = tmp
      end function
      
      public static double code(double x, double y, double z) {
      	double t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	double tmp;
      	if (t_0 <= -1e-61) {
      		tmp = ((z * z) * -0.5) / y;
      	} else if (t_0 <= 2e+112) {
      		tmp = y * 0.5;
      	} else {
      		tmp = x * (x * (0.5 / y));
      	}
      	return tmp;
      }
      
      def code(x, y, z):
      	t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
      	tmp = 0
      	if t_0 <= -1e-61:
      		tmp = ((z * z) * -0.5) / y
      	elif t_0 <= 2e+112:
      		tmp = y * 0.5
      	else:
      		tmp = x * (x * (0.5 / y))
      	return tmp
      
      function code(x, y, z)
      	t_0 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
      	tmp = 0.0
      	if (t_0 <= -1e-61)
      		tmp = Float64(Float64(Float64(z * z) * -0.5) / y);
      	elseif (t_0 <= 2e+112)
      		tmp = Float64(y * 0.5);
      	else
      		tmp = Float64(x * Float64(x * Float64(0.5 / y)));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y, z)
      	t_0 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
      	tmp = 0.0;
      	if (t_0 <= -1e-61)
      		tmp = ((z * z) * -0.5) / y;
      	elseif (t_0 <= 2e+112)
      		tmp = y * 0.5;
      	else
      		tmp = x * (x * (0.5 / y));
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -1e-61], N[(N[(N[(z * z), $MachinePrecision] * -0.5), $MachinePrecision] / y), $MachinePrecision], If[LessEqual[t$95$0, 2e+112], N[(y * 0.5), $MachinePrecision], N[(x * N[(x * N[(0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
      \mathbf{if}\;t\_0 \leq -1 \cdot 10^{-61}:\\
      \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\
      
      \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+112}:\\
      \;\;\;\;y \cdot 0.5\\
      
      \mathbf{else}:\\
      \;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61

        1. Initial program 83.1%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Taylor expanded in z around inf

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
        4. Step-by-step derivation
          1. associate-*r/N/A

            \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot {z}^{2}}{y}} \]
          2. metadata-evalN/A

            \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
          3. associate-*r*N/A

            \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot \left(-1 \cdot {z}^{2}\right)}}{y} \]
          4. mul-1-negN/A

            \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(\mathsf{neg}\left({z}^{2}\right)\right)}}{y} \]
          5. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
          6. mul-1-negN/A

            \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
          7. associate-*r*N/A

            \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right) \cdot {z}^{2}}}{y} \]
          8. metadata-evalN/A

            \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
          9. *-commutativeN/A

            \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
          10. lower-*.f64N/A

            \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
          11. unpow2N/A

            \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
          12. lower-*.f6431.7

            \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
        5. Applied rewrites31.7%

          \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]

        if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 1.9999999999999999e112

        1. Initial program 84.6%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
        4. Step-by-step derivation
          1. lower-*.f6461.4

            \[\leadsto \color{blue}{0.5 \cdot y} \]
        5. Applied rewrites61.4%

          \[\leadsto \color{blue}{0.5 \cdot y} \]

        if 1.9999999999999999e112 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

        1. Initial program 64.3%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}} \]
          2. clear-numN/A

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

            \[\leadsto \frac{1}{\frac{\color{blue}{y \cdot 2}}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
          4. associate-/l*N/A

            \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}}} \]
          5. associate-/r*N/A

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

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

            \[\leadsto \frac{\color{blue}{\frac{1}{y}}}{\frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
          8. lower-/.f6464.4

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\color{blue}{\left(x \cdot x + y \cdot y\right)} - z \cdot z}} \]
          11. associate--l+N/A

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

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\left(y \cdot y - \color{blue}{z \cdot z}\right) + x \cdot x}} \]
          15. difference-of-squaresN/A

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

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

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(\color{blue}{y + z}, y - z, x \cdot x\right)}} \]
          18. lower--.f6471.6

            \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(y + z, \color{blue}{y - z}, x \cdot x\right)}} \]
        4. Applied rewrites71.6%

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

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
        6. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
          2. lower-*.f64N/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
          3. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{{z}^{2}}{y}} \cdot \frac{-1}{2} \]
          4. unpow2N/A

            \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot \frac{-1}{2} \]
          5. lower-*.f6441.5

            \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot -0.5 \]
        7. Applied rewrites41.5%

          \[\leadsto \color{blue}{\frac{z \cdot z}{y} \cdot -0.5} \]
        8. Taylor expanded in x around inf

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
        9. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{\frac{{x}^{2}}{y} \cdot \frac{1}{2}} \]
          2. unpow2N/A

            \[\leadsto \frac{\color{blue}{x \cdot x}}{y} \cdot \frac{1}{2} \]
          3. associate-/l*N/A

            \[\leadsto \color{blue}{\left(x \cdot \frac{x}{y}\right)} \cdot \frac{1}{2} \]
          4. associate-*r*N/A

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

            \[\leadsto x \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{x}{y}\right)} \]
          6. lower-*.f64N/A

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

            \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
          8. lower-*.f64N/A

            \[\leadsto x \cdot \color{blue}{\left(\frac{x}{y} \cdot \frac{1}{2}\right)} \]
          9. lower-/.f6435.9

            \[\leadsto x \cdot \left(\color{blue}{\frac{x}{y}} \cdot 0.5\right) \]
        10. Applied rewrites35.9%

          \[\leadsto \color{blue}{x \cdot \left(\frac{x}{y} \cdot 0.5\right)} \]
        11. Step-by-step derivation
          1. Applied rewrites35.9%

            \[\leadsto x \cdot \left(\frac{0.5}{y} \cdot \color{blue}{x}\right) \]
        12. Recombined 3 regimes into one program.
        13. Final simplification36.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 2 \cdot 10^{+112}:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\ \end{array} \]
        14. Add Preprocessing

        Alternative 6: 51.7% accurate, 0.6× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\left(z \cdot \frac{z}{y}\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \end{array} \end{array} \]
        (FPCore (x y z)
         :precision binary64
         (if (<= (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)) -1e-61)
           (* (* z (/ z y)) -0.5)
           (* 0.5 (fma x (/ x y) y))))
        double code(double x, double y, double z) {
        	double tmp;
        	if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= -1e-61) {
        		tmp = (z * (z / y)) * -0.5;
        	} else {
        		tmp = 0.5 * fma(x, (x / y), y);
        	}
        	return tmp;
        }
        
        function code(x, y, z)
        	tmp = 0.0
        	if (Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0)) <= -1e-61)
        		tmp = Float64(Float64(z * Float64(z / y)) * -0.5);
        	else
        		tmp = Float64(0.5 * fma(x, Float64(x / y), y));
        	end
        	return tmp
        end
        
        code[x_, y_, z_] := If[LessEqual[N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision], -1e-61], N[(N[(z * N[(z / y), $MachinePrecision]), $MachinePrecision] * -0.5), $MachinePrecision], N[(0.5 * N[(x * N[(x / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\
        \;\;\;\;\left(z \cdot \frac{z}{y}\right) \cdot -0.5\\
        
        \mathbf{else}:\\
        \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61

          1. Initial program 83.1%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift-/.f64N/A

              \[\leadsto \color{blue}{\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}} \]
            2. clear-numN/A

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

              \[\leadsto \frac{1}{\frac{\color{blue}{y \cdot 2}}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
            4. associate-/l*N/A

              \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}}} \]
            5. associate-/r*N/A

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

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

              \[\leadsto \frac{\color{blue}{\frac{1}{y}}}{\frac{2}{\left(x \cdot x + y \cdot y\right) - z \cdot z}} \]
            8. lower-/.f6483.0

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

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

              \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\color{blue}{\left(x \cdot x + y \cdot y\right)} - z \cdot z}} \]
            11. associate--l+N/A

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

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

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

              \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\left(y \cdot y - \color{blue}{z \cdot z}\right) + x \cdot x}} \]
            15. difference-of-squaresN/A

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

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

              \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(\color{blue}{y + z}, y - z, x \cdot x\right)}} \]
            18. lower--.f6483.0

              \[\leadsto \frac{\frac{1}{y}}{\frac{2}{\mathsf{fma}\left(y + z, \color{blue}{y - z}, x \cdot x\right)}} \]
          4. Applied rewrites83.0%

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

            \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
          6. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
            2. lower-*.f64N/A

              \[\leadsto \color{blue}{\frac{{z}^{2}}{y} \cdot \frac{-1}{2}} \]
            3. lower-/.f64N/A

              \[\leadsto \color{blue}{\frac{{z}^{2}}{y}} \cdot \frac{-1}{2} \]
            4. unpow2N/A

              \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot \frac{-1}{2} \]
            5. lower-*.f6431.7

              \[\leadsto \frac{\color{blue}{z \cdot z}}{y} \cdot -0.5 \]
          7. Applied rewrites31.7%

            \[\leadsto \color{blue}{\frac{z \cdot z}{y} \cdot -0.5} \]
          8. Step-by-step derivation
            1. Applied rewrites32.5%

              \[\leadsto \left(\frac{z}{y} \cdot z\right) \cdot -0.5 \]

            if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

            1. Initial program 67.8%

              \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
            2. Add Preprocessing
            3. Taylor expanded in z around 0

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2} + {y}^{2}}{y}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} + {x}^{2}}}{y} \]
              2. *-rgt-identityN/A

                \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot 1} + {x}^{2}}{y} \]
              3. *-lft-identityN/A

                \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{1 \cdot {x}^{2}}}{y} \]
              4. *-inversesN/A

                \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{\frac{{y}^{2}}{{y}^{2}}} \cdot {x}^{2}}{y} \]
              5. associate-*l/N/A

                \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{\frac{{y}^{2} \cdot {x}^{2}}{{y}^{2}}}}{y} \]
              6. associate-*r/N/A

                \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot 1 + \color{blue}{{y}^{2} \cdot \frac{{x}^{2}}{{y}^{2}}}}{y} \]
              7. distribute-lft-inN/A

                \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)}}{y} \]
              8. associate-*l/N/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{{y}^{2}}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right)} \]
              9. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(\frac{\color{blue}{y \cdot y}}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
              10. associate-/l*N/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(y \cdot \frac{y}{y}\right)} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
              11. *-inversesN/A

                \[\leadsto \frac{1}{2} \cdot \left(\left(y \cdot \color{blue}{1}\right) \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
              12. *-rgt-identityN/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{y} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
              13. distribute-lft-inN/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(y \cdot 1 + y \cdot \frac{{x}^{2}}{{y}^{2}}\right)} \]
              14. *-rgt-identityN/A

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

                \[\leadsto \frac{1}{2} \cdot \left(y + \color{blue}{\frac{{x}^{2}}{{y}^{2}} \cdot y}\right) \]
              16. associate-/r/N/A

                \[\leadsto \frac{1}{2} \cdot \left(y + \color{blue}{\frac{{x}^{2}}{\frac{{y}^{2}}{y}}}\right) \]
              17. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\frac{\color{blue}{y \cdot y}}{y}}\right) \]
              18. associate-/l*N/A

                \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y \cdot \frac{y}{y}}}\right) \]
              19. *-inversesN/A

                \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{y \cdot \color{blue}{1}}\right) \]
              20. *-rgt-identityN/A

                \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y}}\right) \]
            5. Applied rewrites62.1%

              \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
          9. Recombined 2 regimes into one program.
          10. Final simplification49.3%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\left(z \cdot \frac{z}{y}\right) \cdot -0.5\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \end{array} \]
          11. Add Preprocessing

          Alternative 7: 33.6% accurate, 0.6× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{else}:\\ \;\;\;\;y \cdot 0.5\\ \end{array} \end{array} \]
          (FPCore (x y z)
           :precision binary64
           (if (<= (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)) -1e-61)
             (/ (* (* z z) -0.5) y)
             (* y 0.5)))
          double code(double x, double y, double z) {
          	double tmp;
          	if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= -1e-61) {
          		tmp = ((z * z) * -0.5) / y;
          	} else {
          		tmp = y * 0.5;
          	}
          	return tmp;
          }
          
          real(8) function code(x, y, z)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              real(8) :: tmp
              if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)) <= (-1d-61)) then
                  tmp = ((z * z) * (-0.5d0)) / y
              else
                  tmp = y * 0.5d0
              end if
              code = tmp
          end function
          
          public static double code(double x, double y, double z) {
          	double tmp;
          	if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= -1e-61) {
          		tmp = ((z * z) * -0.5) / y;
          	} else {
          		tmp = y * 0.5;
          	}
          	return tmp;
          }
          
          def code(x, y, z):
          	tmp = 0
          	if ((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= -1e-61:
          		tmp = ((z * z) * -0.5) / y
          	else:
          		tmp = y * 0.5
          	return tmp
          
          function code(x, y, z)
          	tmp = 0.0
          	if (Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0)) <= -1e-61)
          		tmp = Float64(Float64(Float64(z * z) * -0.5) / y);
          	else
          		tmp = Float64(y * 0.5);
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z)
          	tmp = 0.0;
          	if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= -1e-61)
          		tmp = ((z * z) * -0.5) / y;
          	else
          		tmp = y * 0.5;
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_, z_] := If[LessEqual[N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision], -1e-61], N[(N[(N[(z * z), $MachinePrecision] * -0.5), $MachinePrecision] / y), $MachinePrecision], N[(y * 0.5), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\
          \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\
          
          \mathbf{else}:\\
          \;\;\;\;y \cdot 0.5\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < -1e-61

            1. Initial program 83.1%

              \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
            2. Add Preprocessing
            3. Taylor expanded in z around inf

              \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
            4. Step-by-step derivation
              1. associate-*r/N/A

                \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot {z}^{2}}{y}} \]
              2. metadata-evalN/A

                \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
              3. associate-*r*N/A

                \[\leadsto \frac{\color{blue}{\frac{1}{2} \cdot \left(-1 \cdot {z}^{2}\right)}}{y} \]
              4. mul-1-negN/A

                \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(\mathsf{neg}\left({z}^{2}\right)\right)}}{y} \]
              5. lower-/.f64N/A

                \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
              6. mul-1-negN/A

                \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
              7. associate-*r*N/A

                \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right) \cdot {z}^{2}}}{y} \]
              8. metadata-evalN/A

                \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
              9. *-commutativeN/A

                \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
              10. lower-*.f64N/A

                \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
              11. unpow2N/A

                \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
              12. lower-*.f6431.7

                \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
            5. Applied rewrites31.7%

              \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]

            if -1e-61 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

            1. Initial program 67.8%

              \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
            2. Add Preprocessing
            3. Taylor expanded in y around inf

              \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
            4. Step-by-step derivation
              1. lower-*.f6429.7

                \[\leadsto \color{blue}{0.5 \cdot y} \]
            5. Applied rewrites29.7%

              \[\leadsto \color{blue}{0.5 \cdot y} \]
          3. Recombined 2 regimes into one program.
          4. Final simplification30.6%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -1 \cdot 10^{-61}:\\ \;\;\;\;\frac{\left(z \cdot z\right) \cdot -0.5}{y}\\ \mathbf{else}:\\ \;\;\;\;y \cdot 0.5\\ \end{array} \]
          5. Add Preprocessing

          Alternative 8: 34.4% accurate, 6.3× speedup?

          \[\begin{array}{l} \\ y \cdot 0.5 \end{array} \]
          (FPCore (x y z) :precision binary64 (* y 0.5))
          double code(double x, double y, double z) {
          	return y * 0.5;
          }
          
          real(8) function code(x, y, z)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              code = y * 0.5d0
          end function
          
          public static double code(double x, double y, double z) {
          	return y * 0.5;
          }
          
          def code(x, y, z):
          	return y * 0.5
          
          function code(x, y, z)
          	return Float64(y * 0.5)
          end
          
          function tmp = code(x, y, z)
          	tmp = y * 0.5;
          end
          
          code[x_, y_, z_] := N[(y * 0.5), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          y \cdot 0.5
          \end{array}
          
          Derivation
          1. Initial program 74.5%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          2. Add Preprocessing
          3. Taylor expanded in y around inf

            \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
          4. Step-by-step derivation
            1. lower-*.f6430.2

              \[\leadsto \color{blue}{0.5 \cdot y} \]
          5. Applied rewrites30.2%

            \[\leadsto \color{blue}{0.5 \cdot y} \]
          6. Final simplification30.2%

            \[\leadsto y \cdot 0.5 \]
          7. Add Preprocessing

          Developer Target 1: 99.9% accurate, 1.1× speedup?

          \[\begin{array}{l} \\ y \cdot 0.5 - \left(\frac{0.5}{y} \cdot \left(z + x\right)\right) \cdot \left(z - x\right) \end{array} \]
          (FPCore (x y z)
           :precision binary64
           (- (* y 0.5) (* (* (/ 0.5 y) (+ z x)) (- z x))))
          double code(double x, double y, double z) {
          	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
          }
          
          real(8) function code(x, y, z)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              code = (y * 0.5d0) - (((0.5d0 / y) * (z + x)) * (z - x))
          end function
          
          public static double code(double x, double y, double z) {
          	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
          }
          
          def code(x, y, z):
          	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x))
          
          function code(x, y, z)
          	return Float64(Float64(y * 0.5) - Float64(Float64(Float64(0.5 / y) * Float64(z + x)) * Float64(z - x)))
          end
          
          function tmp = code(x, y, z)
          	tmp = (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
          end
          
          code[x_, y_, z_] := N[(N[(y * 0.5), $MachinePrecision] - N[(N[(N[(0.5 / y), $MachinePrecision] * N[(z + x), $MachinePrecision]), $MachinePrecision] * N[(z - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          y \cdot 0.5 - \left(\frac{0.5}{y} \cdot \left(z + x\right)\right) \cdot \left(z - x\right)
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024221 
          (FPCore (x y z)
            :name "Diagrams.TwoD.Apollonian:initialConfig from diagrams-contrib-1.3.0.5, A"
            :precision binary64
          
            :alt
            (! :herbie-platform default (- (* y 1/2) (* (* (/ 1/2 y) (+ z x)) (- z x))))
          
            (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))