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

Percentage Accurate: 69.3% → 99.8%
Time: 1.6min
Alternatives: 9
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 9 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: 69.3% 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: 99.8% accurate, 1.3× speedup?

\[\begin{array}{l} z_m = \left|z\right| \\ 0.5 \cdot \mathsf{fma}\left(\frac{x + z\_m}{y}, x - z\_m, y\right) \end{array} \]
z_m = (fabs.f64 z)
(FPCore (x y z_m)
 :precision binary64
 (* 0.5 (fma (/ (+ x z_m) y) (- x z_m) y)))
z_m = fabs(z);
double code(double x, double y, double z_m) {
	return 0.5 * fma(((x + z_m) / y), (x - z_m), y);
}
z_m = abs(z)
function code(x, y, z_m)
	return Float64(0.5 * fma(Float64(Float64(x + z_m) / y), Float64(x - z_m), y))
end
z_m = N[Abs[z], $MachinePrecision]
code[x_, y_, z$95$m_] := N[(0.5 * N[(N[(N[(x + z$95$m), $MachinePrecision] / y), $MachinePrecision] * N[(x - z$95$m), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
z_m = \left|z\right|

\\
0.5 \cdot \mathsf{fma}\left(\frac{x + z\_m}{y}, x - z\_m, y\right)
\end{array}
Derivation
  1. Initial program 68.0%

    \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
  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 rewrites99.8%

    \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
  5. Step-by-step derivation
    1. Applied rewrites99.8%

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

    Alternative 2: 33.1% accurate, 0.3× speedup?

    \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 4 \cdot 10^{-96}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 10^{+289}:\\ \;\;\;\;\frac{x \cdot x}{y \cdot 2}\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    z_m = (fabs.f64 z)
    (FPCore (x y z_m)
     :precision binary64
     (let* ((t_0 (* z_m (* (/ z_m y) -0.5)))
            (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
       (if (<= t_1 4e-96)
         t_0
         (if (<= t_1 1e+289)
           (/ (* x x) (* y 2.0))
           (if (<= t_1 INFINITY) (* y 0.5) t_0)))))
    z_m = fabs(z);
    double code(double x, double y, double z_m) {
    	double t_0 = z_m * ((z_m / y) * -0.5);
    	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= 4e-96) {
    		tmp = t_0;
    	} else if (t_1 <= 1e+289) {
    		tmp = (x * x) / (y * 2.0);
    	} else if (t_1 <= ((double) INFINITY)) {
    		tmp = y * 0.5;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    z_m = Math.abs(z);
    public static double code(double x, double y, double z_m) {
    	double t_0 = z_m * ((z_m / y) * -0.5);
    	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= 4e-96) {
    		tmp = t_0;
    	} else if (t_1 <= 1e+289) {
    		tmp = (x * x) / (y * 2.0);
    	} else if (t_1 <= Double.POSITIVE_INFINITY) {
    		tmp = y * 0.5;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    z_m = math.fabs(z)
    def code(x, y, z_m):
    	t_0 = z_m * ((z_m / y) * -0.5)
    	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0)
    	tmp = 0
    	if t_1 <= 4e-96:
    		tmp = t_0
    	elif t_1 <= 1e+289:
    		tmp = (x * x) / (y * 2.0)
    	elif t_1 <= math.inf:
    		tmp = y * 0.5
    	else:
    		tmp = t_0
    	return tmp
    
    z_m = abs(z)
    function code(x, y, z_m)
    	t_0 = Float64(z_m * Float64(Float64(z_m / y) * -0.5))
    	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
    	tmp = 0.0
    	if (t_1 <= 4e-96)
    		tmp = t_0;
    	elseif (t_1 <= 1e+289)
    		tmp = Float64(Float64(x * x) / Float64(y * 2.0));
    	elseif (t_1 <= Inf)
    		tmp = Float64(y * 0.5);
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    z_m = abs(z);
    function tmp_2 = code(x, y, z_m)
    	t_0 = z_m * ((z_m / y) * -0.5);
    	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	tmp = 0.0;
    	if (t_1 <= 4e-96)
    		tmp = t_0;
    	elseif (t_1 <= 1e+289)
    		tmp = (x * x) / (y * 2.0);
    	elseif (t_1 <= Inf)
    		tmp = y * 0.5;
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    z_m = N[Abs[z], $MachinePrecision]
    code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(z$95$m * N[(N[(z$95$m / y), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 4e-96], t$95$0, If[LessEqual[t$95$1, 1e+289], N[(N[(x * x), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(y * 0.5), $MachinePrecision], t$95$0]]]]]
    
    \begin{array}{l}
    z_m = \left|z\right|
    
    \\
    \begin{array}{l}
    t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\
    t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
    \mathbf{if}\;t\_1 \leq 4 \cdot 10^{-96}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;t\_1 \leq 10^{+289}:\\
    \;\;\;\;\frac{x \cdot x}{y \cdot 2}\\
    
    \mathbf{elif}\;t\_1 \leq \infty:\\
    \;\;\;\;y \cdot 0.5\\
    
    \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))) < 3.9999999999999996e-96 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

      1. Initial program 59.8%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      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 rewrites99.8%

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

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
      6. Step-by-step derivation
        1. unpow2N/A

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

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

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

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

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

          \[\leadsto z \cdot \color{blue}{\left(\frac{-1}{2} \cdot \frac{z}{y}\right)} \]
        7. lower-/.f6441.5

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

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

      if 3.9999999999999996e-96 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 1.0000000000000001e289

      1. Initial program 99.7%

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

        \[\leadsto \frac{\color{blue}{{x}^{2}}}{y \cdot 2} \]
      4. Step-by-step derivation
        1. unpow2N/A

          \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
        2. lower-*.f6452.3

          \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
      5. Applied rewrites52.3%

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]

      if 1.0000000000000001e289 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

      1. Initial program 65.6%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      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-*.f6431.6

          \[\leadsto \color{blue}{0.5 \cdot y} \]
      5. Applied rewrites31.6%

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification40.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 4 \cdot 10^{-96}:\\ \;\;\;\;z \cdot \left(\frac{z}{y} \cdot -0.5\right)\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 10^{+289}:\\ \;\;\;\;\frac{x \cdot x}{y \cdot 2}\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;z \cdot \left(\frac{z}{y} \cdot -0.5\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 3: 33.1% accurate, 0.3× speedup?

    \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 4 \cdot 10^{-96}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 10^{+289}:\\ \;\;\;\;\left(x \cdot x\right) \cdot \frac{0.5}{y}\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    z_m = (fabs.f64 z)
    (FPCore (x y z_m)
     :precision binary64
     (let* ((t_0 (* z_m (* (/ z_m y) -0.5)))
            (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
       (if (<= t_1 4e-96)
         t_0
         (if (<= t_1 1e+289)
           (* (* x x) (/ 0.5 y))
           (if (<= t_1 INFINITY) (* y 0.5) t_0)))))
    z_m = fabs(z);
    double code(double x, double y, double z_m) {
    	double t_0 = z_m * ((z_m / y) * -0.5);
    	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= 4e-96) {
    		tmp = t_0;
    	} else if (t_1 <= 1e+289) {
    		tmp = (x * x) * (0.5 / y);
    	} else if (t_1 <= ((double) INFINITY)) {
    		tmp = y * 0.5;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    z_m = Math.abs(z);
    public static double code(double x, double y, double z_m) {
    	double t_0 = z_m * ((z_m / y) * -0.5);
    	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= 4e-96) {
    		tmp = t_0;
    	} else if (t_1 <= 1e+289) {
    		tmp = (x * x) * (0.5 / y);
    	} else if (t_1 <= Double.POSITIVE_INFINITY) {
    		tmp = y * 0.5;
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    z_m = math.fabs(z)
    def code(x, y, z_m):
    	t_0 = z_m * ((z_m / y) * -0.5)
    	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0)
    	tmp = 0
    	if t_1 <= 4e-96:
    		tmp = t_0
    	elif t_1 <= 1e+289:
    		tmp = (x * x) * (0.5 / y)
    	elif t_1 <= math.inf:
    		tmp = y * 0.5
    	else:
    		tmp = t_0
    	return tmp
    
    z_m = abs(z)
    function code(x, y, z_m)
    	t_0 = Float64(z_m * Float64(Float64(z_m / y) * -0.5))
    	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
    	tmp = 0.0
    	if (t_1 <= 4e-96)
    		tmp = t_0;
    	elseif (t_1 <= 1e+289)
    		tmp = Float64(Float64(x * x) * Float64(0.5 / y));
    	elseif (t_1 <= Inf)
    		tmp = Float64(y * 0.5);
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    z_m = abs(z);
    function tmp_2 = code(x, y, z_m)
    	t_0 = z_m * ((z_m / y) * -0.5);
    	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	tmp = 0.0;
    	if (t_1 <= 4e-96)
    		tmp = t_0;
    	elseif (t_1 <= 1e+289)
    		tmp = (x * x) * (0.5 / y);
    	elseif (t_1 <= Inf)
    		tmp = y * 0.5;
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    z_m = N[Abs[z], $MachinePrecision]
    code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(z$95$m * N[(N[(z$95$m / y), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 4e-96], t$95$0, If[LessEqual[t$95$1, 1e+289], N[(N[(x * x), $MachinePrecision] * N[(0.5 / y), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(y * 0.5), $MachinePrecision], t$95$0]]]]]
    
    \begin{array}{l}
    z_m = \left|z\right|
    
    \\
    \begin{array}{l}
    t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\
    t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
    \mathbf{if}\;t\_1 \leq 4 \cdot 10^{-96}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;t\_1 \leq 10^{+289}:\\
    \;\;\;\;\left(x \cdot x\right) \cdot \frac{0.5}{y}\\
    
    \mathbf{elif}\;t\_1 \leq \infty:\\
    \;\;\;\;y \cdot 0.5\\
    
    \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))) < 3.9999999999999996e-96 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

      1. Initial program 59.8%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      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 rewrites99.8%

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

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
      6. Step-by-step derivation
        1. unpow2N/A

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

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

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

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

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

          \[\leadsto z \cdot \color{blue}{\left(\frac{-1}{2} \cdot \frac{z}{y}\right)} \]
        7. lower-/.f6441.5

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

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

      if 3.9999999999999996e-96 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 1.0000000000000001e289

      1. Initial program 99.7%

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

        \[\leadsto \frac{\color{blue}{{x}^{2}}}{y \cdot 2} \]
      4. Step-by-step derivation
        1. unpow2N/A

          \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
        2. lower-*.f6452.3

          \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
      5. Applied rewrites52.3%

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
      6. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{x \cdot x}{y \cdot 2}} \]
        2. clear-numN/A

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

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

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

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

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

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

          \[\leadsto \frac{\color{blue}{\frac{1}{2}}}{y} \cdot \left(x \cdot x\right) \]
        9. lower-/.f6452.2

          \[\leadsto \color{blue}{\frac{0.5}{y}} \cdot \left(x \cdot x\right) \]
      7. Applied rewrites52.2%

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

      if 1.0000000000000001e289 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

      1. Initial program 65.6%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      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-*.f6431.6

          \[\leadsto \color{blue}{0.5 \cdot y} \]
      5. Applied rewrites31.6%

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification40.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 4 \cdot 10^{-96}:\\ \;\;\;\;z \cdot \left(\frac{z}{y} \cdot -0.5\right)\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 10^{+289}:\\ \;\;\;\;\left(x \cdot x\right) \cdot \frac{0.5}{y}\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;z \cdot \left(\frac{z}{y} \cdot -0.5\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 69.2% accurate, 0.3× speedup?

    \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := \left(x + z\_m\right) \cdot \left(0.5 \cdot \frac{x - z\_m}{y}\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    z_m = (fabs.f64 z)
    (FPCore (x y z_m)
     :precision binary64
     (let* ((t_0 (* (+ x z_m) (* 0.5 (/ (- x z_m) y))))
            (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
       (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* 0.5 (fma x (/ x y) y)) t_0))))
    z_m = fabs(z);
    double code(double x, double y, double z_m) {
    	double t_0 = (x + z_m) * (0.5 * ((x - z_m) / y));
    	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
    	double tmp;
    	if (t_1 <= 0.0) {
    		tmp = t_0;
    	} else if (t_1 <= ((double) INFINITY)) {
    		tmp = 0.5 * fma(x, (x / y), y);
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    z_m = abs(z)
    function code(x, y, z_m)
    	t_0 = Float64(Float64(x + z_m) * Float64(0.5 * Float64(Float64(x - z_m) / y)))
    	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
    	tmp = 0.0
    	if (t_1 <= 0.0)
    		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
    
    z_m = N[Abs[z], $MachinePrecision]
    code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(N[(x + z$95$m), $MachinePrecision] * N[(0.5 * N[(N[(x - z$95$m), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], 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}
    z_m = \left|z\right|
    
    \\
    \begin{array}{l}
    t_0 := \left(x + z\_m\right) \cdot \left(0.5 \cdot \frac{x - z\_m}{y}\right)\\
    t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
    \mathbf{if}\;t\_1 \leq 0:\\
    \;\;\;\;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))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

      1. Initial program 59.2%

        \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
      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 rewrites99.8%

        \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
      5. Step-by-step derivation
        1. Applied rewrites99.8%

          \[\leadsto 0.5 \cdot \mathsf{fma}\left(\frac{1}{\frac{1}{x + z}}, \frac{\color{blue}{x - z}}{y}, y\right) \]
        2. Taylor expanded in y around 0

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

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

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

            \[\leadsto \frac{x \cdot x - \color{blue}{z \cdot z}}{y} \cdot \frac{1}{2} \]
          4. difference-of-squaresN/A

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \left(z + x\right) \cdot \left(\left(\frac{x}{y} + \color{blue}{\left(\mathsf{neg}\left(\frac{z}{y}\right)\right)}\right) \cdot \frac{1}{2}\right) \]
          17. sub-negN/A

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

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

            \[\leadsto \left(z + x\right) \cdot \left(\color{blue}{\frac{x - z}{y}} \cdot \frac{1}{2}\right) \]
          20. lower--.f6470.0

            \[\leadsto \left(z + x\right) \cdot \left(\frac{\color{blue}{x - z}}{y} \cdot 0.5\right) \]
        4. Applied rewrites70.0%

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

        if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

        1. Initial program 77.7%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        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 rewrites68.7%

          \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
      6. Recombined 2 regimes into one program.
      7. Final simplification69.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\ \;\;\;\;\left(x + z\right) \cdot \left(0.5 \cdot \frac{x - z}{y}\right)\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + z\right) \cdot \left(0.5 \cdot \frac{x - z}{y}\right)\\ \end{array} \]
      8. Add Preprocessing

      Alternative 5: 67.6% accurate, 0.3× speedup?

      \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := 0.5 \cdot \mathsf{fma}\left(-z\_m, \frac{z\_m}{y}, y\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      z_m = (fabs.f64 z)
      (FPCore (x y z_m)
       :precision binary64
       (let* ((t_0 (* 0.5 (fma (- z_m) (/ z_m y) y)))
              (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
         (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* 0.5 (fma x (/ x y) y)) t_0))))
      z_m = fabs(z);
      double code(double x, double y, double z_m) {
      	double t_0 = 0.5 * fma(-z_m, (z_m / y), y);
      	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
      	double tmp;
      	if (t_1 <= 0.0) {
      		tmp = t_0;
      	} else if (t_1 <= ((double) INFINITY)) {
      		tmp = 0.5 * fma(x, (x / y), y);
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      z_m = abs(z)
      function code(x, y, z_m)
      	t_0 = Float64(0.5 * fma(Float64(-z_m), Float64(z_m / y), y))
      	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
      	tmp = 0.0
      	if (t_1 <= 0.0)
      		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
      
      z_m = N[Abs[z], $MachinePrecision]
      code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(0.5 * N[((-z$95$m) * N[(z$95$m / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], 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}
      z_m = \left|z\right|
      
      \\
      \begin{array}{l}
      t_0 := 0.5 \cdot \mathsf{fma}\left(-z\_m, \frac{z\_m}{y}, y\right)\\
      t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
      \mathbf{if}\;t\_1 \leq 0:\\
      \;\;\;\;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))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

        1. Initial program 59.2%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        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-*.f6463.4

            \[\leadsto 0.5 \cdot \left(y - \frac{\color{blue}{z \cdot z}}{y}\right) \]
        5. Applied rewrites63.4%

          \[\leadsto \color{blue}{0.5 \cdot \left(y - \frac{z \cdot z}{y}\right)} \]
        6. Step-by-step derivation
          1. Applied rewrites70.9%

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

          if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

          1. Initial program 77.7%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          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 rewrites68.7%

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

        Alternative 6: 50.0% accurate, 0.3× speedup?

        \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
        z_m = (fabs.f64 z)
        (FPCore (x y z_m)
         :precision binary64
         (let* ((t_0 (* z_m (* (/ z_m y) -0.5)))
                (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
           (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* 0.5 (fma x (/ x y) y)) t_0))))
        z_m = fabs(z);
        double code(double x, double y, double z_m) {
        	double t_0 = z_m * ((z_m / y) * -0.5);
        	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
        	double tmp;
        	if (t_1 <= 0.0) {
        		tmp = t_0;
        	} else if (t_1 <= ((double) INFINITY)) {
        		tmp = 0.5 * fma(x, (x / y), y);
        	} else {
        		tmp = t_0;
        	}
        	return tmp;
        }
        
        z_m = abs(z)
        function code(x, y, z_m)
        	t_0 = Float64(z_m * Float64(Float64(z_m / y) * -0.5))
        	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
        	tmp = 0.0
        	if (t_1 <= 0.0)
        		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
        
        z_m = N[Abs[z], $MachinePrecision]
        code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(z$95$m * N[(N[(z$95$m / y), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], 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}
        z_m = \left|z\right|
        
        \\
        \begin{array}{l}
        t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\
        t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
        \mathbf{if}\;t\_1 \leq 0:\\
        \;\;\;\;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))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

          1. Initial program 59.2%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          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 rewrites99.8%

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

            \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
          6. Step-by-step derivation
            1. unpow2N/A

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

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

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

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

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

              \[\leadsto z \cdot \color{blue}{\left(\frac{-1}{2} \cdot \frac{z}{y}\right)} \]
            7. lower-/.f6441.5

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

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

          if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

          1. Initial program 77.7%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          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 rewrites68.7%

            \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification54.4%

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

        Alternative 7: 35.2% accurate, 0.4× speedup?

        \[\begin{array}{l} z_m = \left|z\right| \\ \begin{array}{l} t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;y \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
        z_m = (fabs.f64 z)
        (FPCore (x y z_m)
         :precision binary64
         (let* ((t_0 (* z_m (* (/ z_m y) -0.5)))
                (t_1 (/ (- (+ (* x x) (* y y)) (* z_m z_m)) (* y 2.0))))
           (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* y 0.5) t_0))))
        z_m = fabs(z);
        double code(double x, double y, double z_m) {
        	double t_0 = z_m * ((z_m / y) * -0.5);
        	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
        	double tmp;
        	if (t_1 <= 0.0) {
        		tmp = t_0;
        	} else if (t_1 <= ((double) INFINITY)) {
        		tmp = y * 0.5;
        	} else {
        		tmp = t_0;
        	}
        	return tmp;
        }
        
        z_m = Math.abs(z);
        public static double code(double x, double y, double z_m) {
        	double t_0 = z_m * ((z_m / y) * -0.5);
        	double t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
        	double tmp;
        	if (t_1 <= 0.0) {
        		tmp = t_0;
        	} else if (t_1 <= Double.POSITIVE_INFINITY) {
        		tmp = y * 0.5;
        	} else {
        		tmp = t_0;
        	}
        	return tmp;
        }
        
        z_m = math.fabs(z)
        def code(x, y, z_m):
        	t_0 = z_m * ((z_m / y) * -0.5)
        	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0)
        	tmp = 0
        	if t_1 <= 0.0:
        		tmp = t_0
        	elif t_1 <= math.inf:
        		tmp = y * 0.5
        	else:
        		tmp = t_0
        	return tmp
        
        z_m = abs(z)
        function code(x, y, z_m)
        	t_0 = Float64(z_m * Float64(Float64(z_m / y) * -0.5))
        	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z_m * z_m)) / Float64(y * 2.0))
        	tmp = 0.0
        	if (t_1 <= 0.0)
        		tmp = t_0;
        	elseif (t_1 <= Inf)
        		tmp = Float64(y * 0.5);
        	else
        		tmp = t_0;
        	end
        	return tmp
        end
        
        z_m = abs(z);
        function tmp_2 = code(x, y, z_m)
        	t_0 = z_m * ((z_m / y) * -0.5);
        	t_1 = (((x * x) + (y * y)) - (z_m * z_m)) / (y * 2.0);
        	tmp = 0.0;
        	if (t_1 <= 0.0)
        		tmp = t_0;
        	elseif (t_1 <= Inf)
        		tmp = y * 0.5;
        	else
        		tmp = t_0;
        	end
        	tmp_2 = tmp;
        end
        
        z_m = N[Abs[z], $MachinePrecision]
        code[x_, y_, z$95$m_] := Block[{t$95$0 = N[(z$95$m * N[(N[(z$95$m / y), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z$95$m * z$95$m), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], t$95$0, If[LessEqual[t$95$1, Infinity], N[(y * 0.5), $MachinePrecision], t$95$0]]]]
        
        \begin{array}{l}
        z_m = \left|z\right|
        
        \\
        \begin{array}{l}
        t_0 := z\_m \cdot \left(\frac{z\_m}{y} \cdot -0.5\right)\\
        t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z\_m \cdot z\_m}{y \cdot 2}\\
        \mathbf{if}\;t\_1 \leq 0:\\
        \;\;\;\;t\_0\\
        
        \mathbf{elif}\;t\_1 \leq \infty:\\
        \;\;\;\;y \cdot 0.5\\
        
        \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))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

          1. Initial program 59.2%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          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 rewrites99.8%

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

            \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
          6. Step-by-step derivation
            1. unpow2N/A

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

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

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

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

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

              \[\leadsto z \cdot \color{blue}{\left(\frac{-1}{2} \cdot \frac{z}{y}\right)} \]
            7. lower-/.f6441.5

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

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

          if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

          1. Initial program 77.7%

            \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
          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-*.f6432.7

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

            \[\leadsto \color{blue}{0.5 \cdot y} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification37.4%

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

        Alternative 8: 99.8% accurate, 1.3× speedup?

        \[\begin{array}{l} z_m = \left|z\right| \\ 0.5 \cdot \mathsf{fma}\left(x + z\_m, \frac{x - z\_m}{y}, y\right) \end{array} \]
        z_m = (fabs.f64 z)
        (FPCore (x y z_m)
         :precision binary64
         (* 0.5 (fma (+ x z_m) (/ (- x z_m) y) y)))
        z_m = fabs(z);
        double code(double x, double y, double z_m) {
        	return 0.5 * fma((x + z_m), ((x - z_m) / y), y);
        }
        
        z_m = abs(z)
        function code(x, y, z_m)
        	return Float64(0.5 * fma(Float64(x + z_m), Float64(Float64(x - z_m) / y), y))
        end
        
        z_m = N[Abs[z], $MachinePrecision]
        code[x_, y_, z$95$m_] := N[(0.5 * N[(N[(x + z$95$m), $MachinePrecision] * N[(N[(x - z$95$m), $MachinePrecision] / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        z_m = \left|z\right|
        
        \\
        0.5 \cdot \mathsf{fma}\left(x + z\_m, \frac{x - z\_m}{y}, y\right)
        \end{array}
        
        Derivation
        1. Initial program 68.0%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        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 rewrites99.8%

          \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
        5. Final simplification99.8%

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

        Alternative 9: 33.5% accurate, 6.3× speedup?

        \[\begin{array}{l} z_m = \left|z\right| \\ y \cdot 0.5 \end{array} \]
        z_m = (fabs.f64 z)
        (FPCore (x y z_m) :precision binary64 (* y 0.5))
        z_m = fabs(z);
        double code(double x, double y, double z_m) {
        	return y * 0.5;
        }
        
        z_m = abs(z)
        real(8) function code(x, y, z_m)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8), intent (in) :: z_m
            code = y * 0.5d0
        end function
        
        z_m = Math.abs(z);
        public static double code(double x, double y, double z_m) {
        	return y * 0.5;
        }
        
        z_m = math.fabs(z)
        def code(x, y, z_m):
        	return y * 0.5
        
        z_m = abs(z)
        function code(x, y, z_m)
        	return Float64(y * 0.5)
        end
        
        z_m = abs(z);
        function tmp = code(x, y, z_m)
        	tmp = y * 0.5;
        end
        
        z_m = N[Abs[z], $MachinePrecision]
        code[x_, y_, z$95$m_] := N[(y * 0.5), $MachinePrecision]
        
        \begin{array}{l}
        z_m = \left|z\right|
        
        \\
        y \cdot 0.5
        \end{array}
        
        Derivation
        1. Initial program 68.0%

          \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
        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-*.f6431.6

            \[\leadsto \color{blue}{0.5 \cdot y} \]
        5. Applied rewrites31.6%

          \[\leadsto \color{blue}{0.5 \cdot y} \]
        6. Final simplification31.6%

          \[\leadsto y \cdot 0.5 \]
        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 2024257 
        (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)))