Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, G

Percentage Accurate: 85.1% → 99.8%
Time: 10.6s
Alternatives: 7
Speedup: 19.1×

Specification

?
\[\begin{array}{l} \\ x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (+ x (/ (exp (* y (log (/ y (+ z y))))) y)))
double code(double x, double y, double z) {
	return x + (exp((y * log((y / (z + y))))) / y);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x + (exp((y * log((y / (z + y))))) / y)
end function
public static double code(double x, double y, double z) {
	return x + (Math.exp((y * Math.log((y / (z + y))))) / y);
}
def code(x, y, z):
	return x + (math.exp((y * math.log((y / (z + y))))) / y)
function code(x, y, z)
	return Float64(x + Float64(exp(Float64(y * log(Float64(y / Float64(z + y))))) / y))
end
function tmp = code(x, y, z)
	tmp = x + (exp((y * log((y / (z + y))))) / y);
end
code[x_, y_, z_] := N[(x + N[(N[Exp[N[(y * N[Log[N[(y / N[(z + y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y}
\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 7 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: 85.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (+ x (/ (exp (* y (log (/ y (+ z y))))) y)))
double code(double x, double y, double z) {
	return x + (exp((y * log((y / (z + y))))) / y);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x + (exp((y * log((y / (z + y))))) / y)
end function
public static double code(double x, double y, double z) {
	return x + (Math.exp((y * Math.log((y / (z + y))))) / y);
}
def code(x, y, z):
	return x + (math.exp((y * math.log((y / (z + y))))) / y)
function code(x, y, z)
	return Float64(x + Float64(exp(Float64(y * log(Float64(y / Float64(z + y))))) / y))
end
function tmp = code(x, y, z)
	tmp = x + (exp((y * log((y / (z + y))))) / y);
end
code[x_, y_, z_] := N[(x + N[(N[Exp[N[(y * N[Log[N[(y / N[(z + y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y}
\end{array}

Alternative 1: 99.8% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -4 \cdot 10^{+46} \lor \neg \left(y \leq 0.002\right):\\ \;\;\;\;x + \frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= y -4e+46) (not (<= y 0.002)))
   (+ x (/ (exp (- z)) y))
   (+ x (/ (pow (exp y) (log (/ y (+ y z)))) y))))
double code(double x, double y, double z) {
	double tmp;
	if ((y <= -4e+46) || !(y <= 0.002)) {
		tmp = x + (exp(-z) / y);
	} else {
		tmp = x + (pow(exp(y), log((y / (y + z)))) / 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) :: tmp
    if ((y <= (-4d+46)) .or. (.not. (y <= 0.002d0))) then
        tmp = x + (exp(-z) / y)
    else
        tmp = x + ((exp(y) ** log((y / (y + z)))) / y)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((y <= -4e+46) || !(y <= 0.002)) {
		tmp = x + (Math.exp(-z) / y);
	} else {
		tmp = x + (Math.pow(Math.exp(y), Math.log((y / (y + z)))) / y);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (y <= -4e+46) or not (y <= 0.002):
		tmp = x + (math.exp(-z) / y)
	else:
		tmp = x + (math.pow(math.exp(y), math.log((y / (y + z)))) / y)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((y <= -4e+46) || !(y <= 0.002))
		tmp = Float64(x + Float64(exp(Float64(-z)) / y));
	else
		tmp = Float64(x + Float64((exp(y) ^ log(Float64(y / Float64(y + z)))) / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((y <= -4e+46) || ~((y <= 0.002)))
		tmp = x + (exp(-z) / y);
	else
		tmp = x + ((exp(y) ^ log((y / (y + z)))) / y);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[y, -4e+46], N[Not[LessEqual[y, 0.002]], $MachinePrecision]], N[(x + N[(N[Exp[(-z)], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], N[(x + N[(N[Power[N[Exp[y], $MachinePrecision], N[Log[N[(y / N[(y + z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -4 \cdot 10^{+46} \lor \neg \left(y \leq 0.002\right):\\
\;\;\;\;x + \frac{e^{-z}}{y}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -4e46 or 2e-3 < y

    1. Initial program 85.6%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. *-commutative85.6%

        \[\leadsto x + \frac{e^{\color{blue}{\log \left(\frac{y}{z + y}\right) \cdot y}}}{y} \]
      2. exp-prod85.6%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{\log \left(\frac{y}{z + y}\right)}\right)}^{y}}}{y} \]
      3. rem-exp-log85.6%

        \[\leadsto x + \frac{{\color{blue}{\left(\frac{y}{z + y}\right)}}^{y}}{y} \]
      4. +-commutative85.6%

        \[\leadsto x + \frac{{\left(\frac{y}{\color{blue}{y + z}}\right)}^{y}}{y} \]
    3. Simplified85.6%

      \[\leadsto \color{blue}{x + \frac{{\left(\frac{y}{y + z}\right)}^{y}}{y}} \]
    4. Taylor expanded in y around inf 100.0%

      \[\leadsto x + \frac{\color{blue}{e^{-1 \cdot z}}}{y} \]
    5. Step-by-step derivation
      1. mul-1-neg100.0%

        \[\leadsto x + \frac{e^{\color{blue}{-z}}}{y} \]
    6. Simplified100.0%

      \[\leadsto x + \frac{\color{blue}{e^{-z}}}{y} \]

    if -4e46 < y < 2e-3

    1. Initial program 84.7%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative99.9%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -4 \cdot 10^{+46} \lor \neg \left(y \leq 0.002\right):\\ \;\;\;\;x + \frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}\\ \end{array} \]

Alternative 2: 99.6% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -205 \lor \neg \left(y \leq 0.45\right):\\ \;\;\;\;x + \frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= y -205.0) (not (<= y 0.45)))
   (+ x (/ (exp (- z)) y))
   (+ x (/ 1.0 y))))
double code(double x, double y, double z) {
	double tmp;
	if ((y <= -205.0) || !(y <= 0.45)) {
		tmp = x + (exp(-z) / y);
	} else {
		tmp = x + (1.0 / 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) :: tmp
    if ((y <= (-205.0d0)) .or. (.not. (y <= 0.45d0))) then
        tmp = x + (exp(-z) / y)
    else
        tmp = x + (1.0d0 / y)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((y <= -205.0) || !(y <= 0.45)) {
		tmp = x + (Math.exp(-z) / y);
	} else {
		tmp = x + (1.0 / y);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (y <= -205.0) or not (y <= 0.45):
		tmp = x + (math.exp(-z) / y)
	else:
		tmp = x + (1.0 / y)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((y <= -205.0) || !(y <= 0.45))
		tmp = Float64(x + Float64(exp(Float64(-z)) / y));
	else
		tmp = Float64(x + Float64(1.0 / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((y <= -205.0) || ~((y <= 0.45)))
		tmp = x + (exp(-z) / y);
	else
		tmp = x + (1.0 / y);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[y, -205.0], N[Not[LessEqual[y, 0.45]], $MachinePrecision]], N[(x + N[(N[Exp[(-z)], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], N[(x + N[(1.0 / y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -205 \lor \neg \left(y \leq 0.45\right):\\
\;\;\;\;x + \frac{e^{-z}}{y}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{1}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -205 or 0.450000000000000011 < y

    1. Initial program 86.4%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. *-commutative86.4%

        \[\leadsto x + \frac{e^{\color{blue}{\log \left(\frac{y}{z + y}\right) \cdot y}}}{y} \]
      2. exp-prod86.4%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{\log \left(\frac{y}{z + y}\right)}\right)}^{y}}}{y} \]
      3. rem-exp-log86.4%

        \[\leadsto x + \frac{{\color{blue}{\left(\frac{y}{z + y}\right)}}^{y}}{y} \]
      4. +-commutative86.4%

        \[\leadsto x + \frac{{\left(\frac{y}{\color{blue}{y + z}}\right)}^{y}}{y} \]
    3. Simplified86.4%

      \[\leadsto \color{blue}{x + \frac{{\left(\frac{y}{y + z}\right)}^{y}}{y}} \]
    4. Taylor expanded in y around inf 100.0%

      \[\leadsto x + \frac{\color{blue}{e^{-1 \cdot z}}}{y} \]
    5. Step-by-step derivation
      1. mul-1-neg100.0%

        \[\leadsto x + \frac{e^{\color{blue}{-z}}}{y} \]
    6. Simplified100.0%

      \[\leadsto x + \frac{\color{blue}{e^{-z}}}{y} \]

    if -205 < y < 0.450000000000000011

    1. Initial program 83.6%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative99.9%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in y around inf 99.4%

      \[\leadsto \color{blue}{\frac{1}{y} + x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -205 \lor \neg \left(y \leq 0.45\right):\\ \;\;\;\;x + \frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \]

Alternative 3: 89.1% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.2 \cdot 10^{+16}:\\ \;\;\;\;\frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= z -1.2e+16) (/ (exp (- z)) y) (+ x (/ 1.0 y))))
double code(double x, double y, double z) {
	double tmp;
	if (z <= -1.2e+16) {
		tmp = exp(-z) / y;
	} else {
		tmp = x + (1.0 / 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) :: tmp
    if (z <= (-1.2d+16)) then
        tmp = exp(-z) / y
    else
        tmp = x + (1.0d0 / y)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (z <= -1.2e+16) {
		tmp = Math.exp(-z) / y;
	} else {
		tmp = x + (1.0 / y);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if z <= -1.2e+16:
		tmp = math.exp(-z) / y
	else:
		tmp = x + (1.0 / y)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (z <= -1.2e+16)
		tmp = Float64(exp(Float64(-z)) / y);
	else
		tmp = Float64(x + Float64(1.0 / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (z <= -1.2e+16)
		tmp = exp(-z) / y;
	else
		tmp = x + (1.0 / y);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[z, -1.2e+16], N[(N[Exp[(-z)], $MachinePrecision] / y), $MachinePrecision], N[(x + N[(1.0 / y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.2 \cdot 10^{+16}:\\
\;\;\;\;\frac{e^{-z}}{y}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{1}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -1.2e16

    1. Initial program 40.9%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod62.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow62.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow62.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative62.8%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified62.8%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in x around 0 38.5%

      \[\leadsto \color{blue}{\frac{e^{\log \left(\frac{y}{y + z}\right) \cdot y}}{y}} \]
    5. Step-by-step derivation
      1. exp-to-pow38.5%

        \[\leadsto \frac{\color{blue}{{\left(\frac{y}{y + z}\right)}^{y}}}{y} \]
      2. +-commutative38.5%

        \[\leadsto \frac{{\left(\frac{y}{\color{blue}{z + y}}\right)}^{y}}{y} \]
    6. Simplified38.5%

      \[\leadsto \color{blue}{\frac{{\left(\frac{y}{z + y}\right)}^{y}}{y}} \]
    7. Taylor expanded in y around inf 63.9%

      \[\leadsto \frac{\color{blue}{e^{-1 \cdot z}}}{y} \]
    8. Step-by-step derivation
      1. mul-1-neg63.9%

        \[\leadsto \frac{e^{\color{blue}{-z}}}{y} \]
    9. Simplified63.9%

      \[\leadsto \frac{\color{blue}{e^{-z}}}{y} \]

    if -1.2e16 < z

    1. Initial program 95.1%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod98.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow98.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow98.8%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative98.8%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified98.8%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in y around inf 95.8%

      \[\leadsto \color{blue}{\frac{1}{y} + x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.2 \cdot 10^{+16}:\\ \;\;\;\;\frac{e^{-z}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \]

Alternative 4: 85.9% accurate, 19.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -7 \cdot 10^{+144}:\\ \;\;\;\;x + \frac{0.5 \cdot \left(z \cdot z\right)}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= z -7e+144) (+ x (/ (* 0.5 (* z z)) y)) (+ x (/ 1.0 y))))
double code(double x, double y, double z) {
	double tmp;
	if (z <= -7e+144) {
		tmp = x + ((0.5 * (z * z)) / y);
	} else {
		tmp = x + (1.0 / 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) :: tmp
    if (z <= (-7d+144)) then
        tmp = x + ((0.5d0 * (z * z)) / y)
    else
        tmp = x + (1.0d0 / y)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (z <= -7e+144) {
		tmp = x + ((0.5 * (z * z)) / y);
	} else {
		tmp = x + (1.0 / y);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if z <= -7e+144:
		tmp = x + ((0.5 * (z * z)) / y)
	else:
		tmp = x + (1.0 / y)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (z <= -7e+144)
		tmp = Float64(x + Float64(Float64(0.5 * Float64(z * z)) / y));
	else
		tmp = Float64(x + Float64(1.0 / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (z <= -7e+144)
		tmp = x + ((0.5 * (z * z)) / y);
	else
		tmp = x + (1.0 / y);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[z, -7e+144], N[(x + N[(N[(0.5 * N[(z * z), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], N[(x + N[(1.0 / y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -7 \cdot 10^{+144}:\\
\;\;\;\;x + \frac{0.5 \cdot \left(z \cdot z\right)}{y}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{1}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -6.9999999999999996e144

    1. Initial program 44.5%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. *-commutative44.5%

        \[\leadsto x + \frac{e^{\color{blue}{\log \left(\frac{y}{z + y}\right) \cdot y}}}{y} \]
      2. exp-prod44.5%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{\log \left(\frac{y}{z + y}\right)}\right)}^{y}}}{y} \]
      3. rem-exp-log44.5%

        \[\leadsto x + \frac{{\color{blue}{\left(\frac{y}{z + y}\right)}}^{y}}{y} \]
      4. +-commutative44.5%

        \[\leadsto x + \frac{{\left(\frac{y}{\color{blue}{y + z}}\right)}^{y}}{y} \]
    3. Simplified44.5%

      \[\leadsto \color{blue}{x + \frac{{\left(\frac{y}{y + z}\right)}^{y}}{y}} \]
    4. Taylor expanded in z around 0 61.7%

      \[\leadsto x + \color{blue}{\left(\frac{1}{y} + \left(-1 \cdot \frac{z}{y} + \left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) \cdot {z}^{2}\right)\right)} \]
    5. Step-by-step derivation
      1. +-commutative61.7%

        \[\leadsto x + \left(\frac{1}{y} + \color{blue}{\left(\left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) \cdot {z}^{2} + -1 \cdot \frac{z}{y}\right)}\right) \]
      2. mul-1-neg61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) \cdot {z}^{2} + \color{blue}{\left(-\frac{z}{y}\right)}\right)\right) \]
      3. unsub-neg61.7%

        \[\leadsto x + \left(\frac{1}{y} + \color{blue}{\left(\left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) \cdot {z}^{2} - \frac{z}{y}\right)}\right) \]
      4. *-commutative61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\color{blue}{{z}^{2} \cdot \left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right)} - \frac{z}{y}\right)\right) \]
      5. unpow261.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\color{blue}{\left(z \cdot z\right)} \cdot \left(0.5 \cdot \frac{1}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) - \frac{z}{y}\right)\right) \]
      6. associate-*r/61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\color{blue}{\frac{0.5 \cdot 1}{y}} + 0.5 \cdot \frac{1}{{y}^{2}}\right) - \frac{z}{y}\right)\right) \]
      7. metadata-eval61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\frac{\color{blue}{0.5}}{y} + 0.5 \cdot \frac{1}{{y}^{2}}\right) - \frac{z}{y}\right)\right) \]
      8. associate-*r/61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\frac{0.5}{y} + \color{blue}{\frac{0.5 \cdot 1}{{y}^{2}}}\right) - \frac{z}{y}\right)\right) \]
      9. metadata-eval61.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\frac{0.5}{y} + \frac{\color{blue}{0.5}}{{y}^{2}}\right) - \frac{z}{y}\right)\right) \]
      10. unpow261.7%

        \[\leadsto x + \left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\frac{0.5}{y} + \frac{0.5}{\color{blue}{y \cdot y}}\right) - \frac{z}{y}\right)\right) \]
    6. Simplified61.7%

      \[\leadsto x + \color{blue}{\left(\frac{1}{y} + \left(\left(z \cdot z\right) \cdot \left(\frac{0.5}{y} + \frac{0.5}{y \cdot y}\right) - \frac{z}{y}\right)\right)} \]
    7. Taylor expanded in y around inf 62.9%

      \[\leadsto x + \color{blue}{\frac{\left(1 + 0.5 \cdot {z}^{2}\right) - z}{y}} \]
    8. Step-by-step derivation
      1. associate--l+62.9%

        \[\leadsto x + \frac{\color{blue}{1 + \left(0.5 \cdot {z}^{2} - z\right)}}{y} \]
      2. unpow262.9%

        \[\leadsto x + \frac{1 + \left(0.5 \cdot \color{blue}{\left(z \cdot z\right)} - z\right)}{y} \]
    9. Simplified62.9%

      \[\leadsto x + \color{blue}{\frac{1 + \left(0.5 \cdot \left(z \cdot z\right) - z\right)}{y}} \]
    10. Taylor expanded in z around inf 62.9%

      \[\leadsto x + \frac{1 + \color{blue}{0.5 \cdot {z}^{2}}}{y} \]
    11. Step-by-step derivation
      1. unpow262.9%

        \[\leadsto x + \frac{1 + 0.5 \cdot \color{blue}{\left(z \cdot z\right)}}{y} \]
      2. associate-*r*62.9%

        \[\leadsto x + \frac{1 + \color{blue}{\left(0.5 \cdot z\right) \cdot z}}{y} \]
      3. *-commutative62.9%

        \[\leadsto x + \frac{1 + \color{blue}{\left(z \cdot 0.5\right)} \cdot z}{y} \]
    12. Simplified62.9%

      \[\leadsto x + \frac{1 + \color{blue}{\left(z \cdot 0.5\right) \cdot z}}{y} \]
    13. Taylor expanded in z around inf 62.9%

      \[\leadsto x + \color{blue}{0.5 \cdot \frac{{z}^{2}}{y}} \]
    14. Step-by-step derivation
      1. unpow262.9%

        \[\leadsto x + 0.5 \cdot \frac{\color{blue}{z \cdot z}}{y} \]
      2. associate-*r/62.9%

        \[\leadsto x + \color{blue}{\frac{0.5 \cdot \left(z \cdot z\right)}{y}} \]
    15. Simplified62.9%

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

    if -6.9999999999999996e144 < z

    1. Initial program 89.8%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod94.6%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow94.6%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow94.6%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative94.6%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified94.6%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in y around inf 91.0%

      \[\leadsto \color{blue}{\frac{1}{y} + x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -7 \cdot 10^{+144}:\\ \;\;\;\;x + \frac{0.5 \cdot \left(z \cdot z\right)}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{1}{y}\\ \end{array} \]

Alternative 5: 67.9% accurate, 29.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -0.0275:\\ \;\;\;\;x\\ \mathbf{elif}\;y \leq 5 \cdot 10^{-41}:\\ \;\;\;\;\frac{1}{y}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y -0.0275) x (if (<= y 5e-41) (/ 1.0 y) x)))
double code(double x, double y, double z) {
	double tmp;
	if (y <= -0.0275) {
		tmp = x;
	} else if (y <= 5e-41) {
		tmp = 1.0 / y;
	} else {
		tmp = x;
	}
	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 (y <= (-0.0275d0)) then
        tmp = x
    else if (y <= 5d-41) then
        tmp = 1.0d0 / y
    else
        tmp = x
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= -0.0275) {
		tmp = x;
	} else if (y <= 5e-41) {
		tmp = 1.0 / y;
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= -0.0275:
		tmp = x
	elif y <= 5e-41:
		tmp = 1.0 / y
	else:
		tmp = x
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= -0.0275)
		tmp = x;
	elseif (y <= 5e-41)
		tmp = Float64(1.0 / y);
	else
		tmp = x;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= -0.0275)
		tmp = x;
	elseif (y <= 5e-41)
		tmp = 1.0 / y;
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, -0.0275], x, If[LessEqual[y, 5e-41], N[(1.0 / y), $MachinePrecision], x]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -0.0275:\\
\;\;\;\;x\\

\mathbf{elif}\;y \leq 5 \cdot 10^{-41}:\\
\;\;\;\;\frac{1}{y}\\

\mathbf{else}:\\
\;\;\;\;x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -0.0275000000000000001 or 4.9999999999999996e-41 < y

    1. Initial program 87.2%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod87.2%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow87.2%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow87.2%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative87.2%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified87.2%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in x around inf 67.9%

      \[\leadsto \color{blue}{x} \]

    if -0.0275000000000000001 < y < 4.9999999999999996e-41

    1. Initial program 82.1%

      \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
    2. Step-by-step derivation
      1. exp-prod99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      2. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
      3. sqr-pow99.9%

        \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
      4. +-commutative99.9%

        \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
    4. Taylor expanded in y around 0 79.9%

      \[\leadsto \color{blue}{\frac{1}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification72.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -0.0275:\\ \;\;\;\;x\\ \mathbf{elif}\;y \leq 5 \cdot 10^{-41}:\\ \;\;\;\;\frac{1}{y}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]

Alternative 6: 84.7% accurate, 42.2× speedup?

\[\begin{array}{l} \\ x + \frac{1}{y} \end{array} \]
(FPCore (x y z) :precision binary64 (+ x (/ 1.0 y)))
double code(double x, double y, double z) {
	return x + (1.0 / y);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x + (1.0d0 / y)
end function
public static double code(double x, double y, double z) {
	return x + (1.0 / y);
}
def code(x, y, z):
	return x + (1.0 / y)
function code(x, y, z)
	return Float64(x + Float64(1.0 / y))
end
function tmp = code(x, y, z)
	tmp = x + (1.0 / y);
end
code[x_, y_, z_] := N[(x + N[(1.0 / y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{1}{y}
\end{array}
Derivation
  1. Initial program 85.2%

    \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
  2. Step-by-step derivation
    1. exp-prod92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
    2. sqr-pow92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
    3. sqr-pow92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
    4. +-commutative92.2%

      \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
  3. Simplified92.2%

    \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
  4. Taylor expanded in y around inf 85.5%

    \[\leadsto \color{blue}{\frac{1}{y} + x} \]
  5. Final simplification85.5%

    \[\leadsto x + \frac{1}{y} \]

Alternative 7: 49.9% accurate, 211.0× speedup?

\[\begin{array}{l} \\ x \end{array} \]
(FPCore (x y z) :precision binary64 x)
double code(double x, double y, double z) {
	return x;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x
end function
public static double code(double x, double y, double z) {
	return x;
}
def code(x, y, z):
	return x
function code(x, y, z)
	return x
end
function tmp = code(x, y, z)
	tmp = x;
end
code[x_, y_, z_] := x
\begin{array}{l}

\\
x
\end{array}
Derivation
  1. Initial program 85.2%

    \[x + \frac{e^{y \cdot \log \left(\frac{y}{z + y}\right)}}{y} \]
  2. Step-by-step derivation
    1. exp-prod92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
    2. sqr-pow92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)} \cdot {\left(e^{y}\right)}^{\left(\frac{\log \left(\frac{y}{z + y}\right)}{2}\right)}}}{y} \]
    3. sqr-pow92.2%

      \[\leadsto x + \frac{\color{blue}{{\left(e^{y}\right)}^{\log \left(\frac{y}{z + y}\right)}}}{y} \]
    4. +-commutative92.2%

      \[\leadsto x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{\color{blue}{y + z}}\right)}}{y} \]
  3. Simplified92.2%

    \[\leadsto \color{blue}{x + \frac{{\left(e^{y}\right)}^{\log \left(\frac{y}{y + z}\right)}}{y}} \]
  4. Taylor expanded in x around inf 48.7%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification48.7%

    \[\leadsto x \]

Developer target: 91.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{y}{z + y} < 7.11541576 \cdot 10^{-315}:\\ \;\;\;\;x + \frac{e^{\frac{-1}{z}}}{y}\\ \mathbf{else}:\\ \;\;\;\;x + \frac{e^{\log \left({\left(\frac{y}{y + z}\right)}^{y}\right)}}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (< (/ y (+ z y)) 7.11541576e-315)
   (+ x (/ (exp (/ -1.0 z)) y))
   (+ x (/ (exp (log (pow (/ y (+ y z)) y))) y))))
double code(double x, double y, double z) {
	double tmp;
	if ((y / (z + y)) < 7.11541576e-315) {
		tmp = x + (exp((-1.0 / z)) / y);
	} else {
		tmp = x + (exp(log(pow((y / (y + z)), y))) / 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) :: tmp
    if ((y / (z + y)) < 7.11541576d-315) then
        tmp = x + (exp(((-1.0d0) / z)) / y)
    else
        tmp = x + (exp(log(((y / (y + z)) ** y))) / y)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((y / (z + y)) < 7.11541576e-315) {
		tmp = x + (Math.exp((-1.0 / z)) / y);
	} else {
		tmp = x + (Math.exp(Math.log(Math.pow((y / (y + z)), y))) / y);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (y / (z + y)) < 7.11541576e-315:
		tmp = x + (math.exp((-1.0 / z)) / y)
	else:
		tmp = x + (math.exp(math.log(math.pow((y / (y + z)), y))) / y)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (Float64(y / Float64(z + y)) < 7.11541576e-315)
		tmp = Float64(x + Float64(exp(Float64(-1.0 / z)) / y));
	else
		tmp = Float64(x + Float64(exp(log((Float64(y / Float64(y + z)) ^ y))) / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((y / (z + y)) < 7.11541576e-315)
		tmp = x + (exp((-1.0 / z)) / y);
	else
		tmp = x + (exp(log(((y / (y + z)) ^ y))) / y);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Less[N[(y / N[(z + y), $MachinePrecision]), $MachinePrecision], 7.11541576e-315], N[(x + N[(N[Exp[N[(-1.0 / z), $MachinePrecision]], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], N[(x + N[(N[Exp[N[Log[N[Power[N[(y / N[(y + z), $MachinePrecision]), $MachinePrecision], y], $MachinePrecision]], $MachinePrecision]], $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{y}{z + y} < 7.11541576 \cdot 10^{-315}:\\
\;\;\;\;x + \frac{e^{\frac{-1}{z}}}{y}\\

\mathbf{else}:\\
\;\;\;\;x + \frac{e^{\log \left({\left(\frac{y}{y + z}\right)}^{y}\right)}}{y}\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2023200 
(FPCore (x y z)
  :name "Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, G"
  :precision binary64

  :herbie-target
  (if (< (/ y (+ z y)) 7.11541576e-315) (+ x (/ (exp (/ -1.0 z)) y)) (+ x (/ (exp (log (pow (/ y (+ y z)) y))) y)))

  (+ x (/ (exp (* y (log (/ y (+ z y))))) y)))