Numeric.SpecFunctions:incompleteBetaApprox from math-functions-0.1.5.2, B

Percentage Accurate: 96.6% → 96.6%
Time: 7.7s
Alternatives: 6
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (* x (exp (+ (* y (- (log z) t)) (* a (- (log (- 1.0 z)) b))))))
double code(double x, double y, double z, double t, double a, double b) {
	return x * exp(((y * (log(z) - t)) + (a * (log((1.0 - z)) - b))));
}
real(8) function code(x, y, z, t, a, b)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = x * exp(((y * (log(z) - t)) + (a * (log((1.0d0 - z)) - b))))
end function
public static double code(double x, double y, double z, double t, double a, double b) {
	return x * Math.exp(((y * (Math.log(z) - t)) + (a * (Math.log((1.0 - z)) - b))));
}
def code(x, y, z, t, a, b):
	return x * math.exp(((y * (math.log(z) - t)) + (a * (math.log((1.0 - z)) - b))))
function code(x, y, z, t, a, b)
	return Float64(x * exp(Float64(Float64(y * Float64(log(z) - t)) + Float64(a * Float64(log(Float64(1.0 - z)) - b)))))
end
function tmp = code(x, y, z, t, a, b)
	tmp = x * exp(((y * (log(z) - t)) + (a * (log((1.0 - z)) - b))));
end
code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[(N[(y * N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[Log[N[(1.0 - z), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 6 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: 96.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (* x (exp (+ (* y (- (log z) t)) (* a (- (log (- 1.0 z)) b))))))
double code(double x, double y, double z, double t, double a, double b) {
	return x * exp(((y * (log(z) - t)) + (a * (log((1.0 - z)) - b))));
}
real(8) function code(x, y, z, t, a, b)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = x * exp(((y * (log(z) - t)) + (a * (log((1.0d0 - z)) - b))))
end function
public static double code(double x, double y, double z, double t, double a, double b) {
	return x * Math.exp(((y * (Math.log(z) - t)) + (a * (Math.log((1.0 - z)) - b))));
}
def code(x, y, z, t, a, b):
	return x * math.exp(((y * (math.log(z) - t)) + (a * (math.log((1.0 - z)) - b))))
function code(x, y, z, t, a, b)
	return Float64(x * exp(Float64(Float64(y * Float64(log(z) - t)) + Float64(a * Float64(log(Float64(1.0 - z)) - b)))))
end
function tmp = code(x, y, z, t, a, b)
	tmp = x * exp(((y * (log(z) - t)) + (a * (log((1.0 - z)) - b))));
end
code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[(N[(y * N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[Log[N[(1.0 - z), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)}
\end{array}

Alternative 1: 96.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{\left(\log \left(1 - z\right) - b\right) \cdot a + \left(\log z - t\right) \cdot y} \cdot x \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (* (exp (+ (* (- (log (- 1.0 z)) b) a) (* (- (log z) t) y))) x))
double code(double x, double y, double z, double t, double a, double b) {
	return exp((((log((1.0 - z)) - b) * a) + ((log(z) - t) * y))) * x;
}
real(8) function code(x, y, z, t, a, b)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp((((log((1.0d0 - z)) - b) * a) + ((log(z) - t) * y))) * x
end function
public static double code(double x, double y, double z, double t, double a, double b) {
	return Math.exp((((Math.log((1.0 - z)) - b) * a) + ((Math.log(z) - t) * y))) * x;
}
def code(x, y, z, t, a, b):
	return math.exp((((math.log((1.0 - z)) - b) * a) + ((math.log(z) - t) * y))) * x
function code(x, y, z, t, a, b)
	return Float64(exp(Float64(Float64(Float64(log(Float64(1.0 - z)) - b) * a) + Float64(Float64(log(z) - t) * y))) * x)
end
function tmp = code(x, y, z, t, a, b)
	tmp = exp((((log((1.0 - z)) - b) * a) + ((log(z) - t) * y))) * x;
end
code[x_, y_, z_, t_, a_, b_] := N[(N[Exp[N[(N[(N[(N[Log[N[(1.0 - z), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] * a), $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision]
\begin{array}{l}

\\
e^{\left(\log \left(1 - z\right) - b\right) \cdot a + \left(\log z - t\right) \cdot y} \cdot x
\end{array}
Derivation
  1. Initial program 97.7%

    \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
  2. Add Preprocessing
  3. Final simplification97.7%

    \[\leadsto e^{\left(\log \left(1 - z\right) - b\right) \cdot a + \left(\log z - t\right) \cdot y} \cdot x \]
  4. Add Preprocessing

Alternative 2: 87.1% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := {\left(\frac{z}{e^{t}}\right)}^{y} \cdot x\\ \mathbf{if}\;y \leq -1.25 \cdot 10^{-6}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y \leq 6.5 \cdot 10^{-23}:\\ \;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (let* ((t_1 (* (pow (/ z (exp t)) y) x)))
   (if (<= y -1.25e-6)
     t_1
     (if (<= y 6.5e-23) (* (exp (* (- (- z) b) a)) x) t_1))))
double code(double x, double y, double z, double t, double a, double b) {
	double t_1 = pow((z / exp(t)), y) * x;
	double tmp;
	if (y <= -1.25e-6) {
		tmp = t_1;
	} else if (y <= 6.5e-23) {
		tmp = exp(((-z - b) * a)) * x;
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a, b)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_1
    real(8) :: tmp
    t_1 = ((z / exp(t)) ** y) * x
    if (y <= (-1.25d-6)) then
        tmp = t_1
    else if (y <= 6.5d-23) then
        tmp = exp(((-z - b) * a)) * x
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a, double b) {
	double t_1 = Math.pow((z / Math.exp(t)), y) * x;
	double tmp;
	if (y <= -1.25e-6) {
		tmp = t_1;
	} else if (y <= 6.5e-23) {
		tmp = Math.exp(((-z - b) * a)) * x;
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z, t, a, b):
	t_1 = math.pow((z / math.exp(t)), y) * x
	tmp = 0
	if y <= -1.25e-6:
		tmp = t_1
	elif y <= 6.5e-23:
		tmp = math.exp(((-z - b) * a)) * x
	else:
		tmp = t_1
	return tmp
function code(x, y, z, t, a, b)
	t_1 = Float64((Float64(z / exp(t)) ^ y) * x)
	tmp = 0.0
	if (y <= -1.25e-6)
		tmp = t_1;
	elseif (y <= 6.5e-23)
		tmp = Float64(exp(Float64(Float64(Float64(-z) - b) * a)) * x);
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a, b)
	t_1 = ((z / exp(t)) ^ y) * x;
	tmp = 0.0;
	if (y <= -1.25e-6)
		tmp = t_1;
	elseif (y <= 6.5e-23)
		tmp = exp(((-z - b) * a)) * x;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_, b_] := Block[{t$95$1 = N[(N[Power[N[(z / N[Exp[t], $MachinePrecision]), $MachinePrecision], y], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[y, -1.25e-6], t$95$1, If[LessEqual[y, 6.5e-23], N[(N[Exp[N[(N[((-z) - b), $MachinePrecision] * a), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := {\left(\frac{z}{e^{t}}\right)}^{y} \cdot x\\
\mathbf{if}\;y \leq -1.25 \cdot 10^{-6}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y \leq 6.5 \cdot 10^{-23}:\\
\;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -1.2500000000000001e-6 or 6.5e-23 < y

    1. Initial program 97.9%

      \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

      \[\leadsto x \cdot \color{blue}{e^{y \cdot \left(\log z - t\right)}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto x \cdot e^{\color{blue}{\left(\log z - t\right) \cdot y}} \]
      2. exp-prodN/A

        \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
      3. lower-pow.f64N/A

        \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
      4. exp-diffN/A

        \[\leadsto x \cdot {\color{blue}{\left(\frac{e^{\log z}}{e^{t}}\right)}}^{y} \]
      5. rem-exp-logN/A

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

        \[\leadsto x \cdot {\color{blue}{\left(\frac{z}{e^{t}}\right)}}^{y} \]
      7. lower-exp.f6488.8

        \[\leadsto x \cdot {\left(\frac{z}{\color{blue}{e^{t}}}\right)}^{y} \]
    5. Applied rewrites88.8%

      \[\leadsto x \cdot \color{blue}{{\left(\frac{z}{e^{t}}\right)}^{y}} \]

    if -1.2500000000000001e-6 < y < 6.5e-23

    1. Initial program 97.5%

      \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto x \cdot e^{\color{blue}{a \cdot \left(\log \left(1 - z\right) - b\right)}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
      2. lower-*.f64N/A

        \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
      3. lower--.f64N/A

        \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right)} \cdot a} \]
      4. sub-negN/A

        \[\leadsto x \cdot e^{\left(\log \color{blue}{\left(1 + \left(\mathsf{neg}\left(z\right)\right)\right)} - b\right) \cdot a} \]
      5. lower-log1p.f64N/A

        \[\leadsto x \cdot e^{\left(\color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(z\right)\right)} - b\right) \cdot a} \]
      6. lower-neg.f6485.1

        \[\leadsto x \cdot e^{\left(\mathsf{log1p}\left(\color{blue}{-z}\right) - b\right) \cdot a} \]
    5. Applied rewrites85.1%

      \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{log1p}\left(-z\right) - b\right) \cdot a}} \]
    6. Taylor expanded in z around 0

      \[\leadsto x \cdot e^{\left(-1 \cdot z - b\right) \cdot a} \]
    7. Step-by-step derivation
      1. Applied rewrites85.1%

        \[\leadsto x \cdot e^{\left(\left(-z\right) - b\right) \cdot a} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification87.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.25 \cdot 10^{-6}:\\ \;\;\;\;{\left(\frac{z}{e^{t}}\right)}^{y} \cdot x\\ \mathbf{elif}\;y \leq 6.5 \cdot 10^{-23}:\\ \;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{z}{e^{t}}\right)}^{y} \cdot x\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 76.6% accurate, 2.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := {z}^{y} \cdot x\\ \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y \leq 9.2 \cdot 10^{+31}:\\ \;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
    (FPCore (x y z t a b)
     :precision binary64
     (let* ((t_1 (* (pow z y) x)))
       (if (<= y -1.95e+34)
         t_1
         (if (<= y 9.2e+31) (* (exp (* (- (- z) b) a)) x) t_1))))
    double code(double x, double y, double z, double t, double a, double b) {
    	double t_1 = pow(z, y) * x;
    	double tmp;
    	if (y <= -1.95e+34) {
    		tmp = t_1;
    	} else if (y <= 9.2e+31) {
    		tmp = exp(((-z - b) * a)) * x;
    	} else {
    		tmp = t_1;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y, z, t, a, b)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        real(8), intent (in) :: t
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        real(8) :: t_1
        real(8) :: tmp
        t_1 = (z ** y) * x
        if (y <= (-1.95d+34)) then
            tmp = t_1
        else if (y <= 9.2d+31) then
            tmp = exp(((-z - b) * a)) * x
        else
            tmp = t_1
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z, double t, double a, double b) {
    	double t_1 = Math.pow(z, y) * x;
    	double tmp;
    	if (y <= -1.95e+34) {
    		tmp = t_1;
    	} else if (y <= 9.2e+31) {
    		tmp = Math.exp(((-z - b) * a)) * x;
    	} else {
    		tmp = t_1;
    	}
    	return tmp;
    }
    
    def code(x, y, z, t, a, b):
    	t_1 = math.pow(z, y) * x
    	tmp = 0
    	if y <= -1.95e+34:
    		tmp = t_1
    	elif y <= 9.2e+31:
    		tmp = math.exp(((-z - b) * a)) * x
    	else:
    		tmp = t_1
    	return tmp
    
    function code(x, y, z, t, a, b)
    	t_1 = Float64((z ^ y) * x)
    	tmp = 0.0
    	if (y <= -1.95e+34)
    		tmp = t_1;
    	elseif (y <= 9.2e+31)
    		tmp = Float64(exp(Float64(Float64(Float64(-z) - b) * a)) * x);
    	else
    		tmp = t_1;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z, t, a, b)
    	t_1 = (z ^ y) * x;
    	tmp = 0.0;
    	if (y <= -1.95e+34)
    		tmp = t_1;
    	elseif (y <= 9.2e+31)
    		tmp = exp(((-z - b) * a)) * x;
    	else
    		tmp = t_1;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_, t_, a_, b_] := Block[{t$95$1 = N[(N[Power[z, y], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[y, -1.95e+34], t$95$1, If[LessEqual[y, 9.2e+31], N[(N[Exp[N[(N[((-z) - b), $MachinePrecision] * a), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision], t$95$1]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := {z}^{y} \cdot x\\
    \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\
    \;\;\;\;t\_1\\
    
    \mathbf{elif}\;y \leq 9.2 \cdot 10^{+31}:\\
    \;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if y < -1.9500000000000001e34 or 9.1999999999999998e31 < y

      1. Initial program 99.1%

        \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in a around 0

        \[\leadsto x \cdot \color{blue}{e^{y \cdot \left(\log z - t\right)}} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto x \cdot e^{\color{blue}{\left(\log z - t\right) \cdot y}} \]
        2. exp-prodN/A

          \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
        3. lower-pow.f64N/A

          \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
        4. exp-diffN/A

          \[\leadsto x \cdot {\color{blue}{\left(\frac{e^{\log z}}{e^{t}}\right)}}^{y} \]
        5. rem-exp-logN/A

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

          \[\leadsto x \cdot {\color{blue}{\left(\frac{z}{e^{t}}\right)}}^{y} \]
        7. lower-exp.f6490.5

          \[\leadsto x \cdot {\left(\frac{z}{\color{blue}{e^{t}}}\right)}^{y} \]
      5. Applied rewrites90.5%

        \[\leadsto x \cdot \color{blue}{{\left(\frac{z}{e^{t}}\right)}^{y}} \]
      6. Taylor expanded in t around 0

        \[\leadsto x \cdot {z}^{\color{blue}{y}} \]
      7. Step-by-step derivation
        1. Applied rewrites75.0%

          \[\leadsto x \cdot {z}^{\color{blue}{y}} \]

        if -1.9500000000000001e34 < y < 9.1999999999999998e31

        1. Initial program 96.6%

          \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in y around 0

          \[\leadsto x \cdot e^{\color{blue}{a \cdot \left(\log \left(1 - z\right) - b\right)}} \]
        4. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
          2. lower-*.f64N/A

            \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
          3. lower--.f64N/A

            \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right)} \cdot a} \]
          4. sub-negN/A

            \[\leadsto x \cdot e^{\left(\log \color{blue}{\left(1 + \left(\mathsf{neg}\left(z\right)\right)\right)} - b\right) \cdot a} \]
          5. lower-log1p.f64N/A

            \[\leadsto x \cdot e^{\left(\color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(z\right)\right)} - b\right) \cdot a} \]
          6. lower-neg.f6481.6

            \[\leadsto x \cdot e^{\left(\mathsf{log1p}\left(\color{blue}{-z}\right) - b\right) \cdot a} \]
        5. Applied rewrites81.6%

          \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{log1p}\left(-z\right) - b\right) \cdot a}} \]
        6. Taylor expanded in z around 0

          \[\leadsto x \cdot e^{\left(-1 \cdot z - b\right) \cdot a} \]
        7. Step-by-step derivation
          1. Applied rewrites81.6%

            \[\leadsto x \cdot e^{\left(\left(-z\right) - b\right) \cdot a} \]
        8. Recombined 2 regimes into one program.
        9. Final simplification78.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\ \;\;\;\;{z}^{y} \cdot x\\ \mathbf{elif}\;y \leq 9.2 \cdot 10^{+31}:\\ \;\;\;\;e^{\left(\left(-z\right) - b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;{z}^{y} \cdot x\\ \end{array} \]
        10. Add Preprocessing

        Alternative 4: 73.4% accurate, 2.6× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_1 := {z}^{y} \cdot x\\ \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y \leq 6.8 \cdot 10^{+31}:\\ \;\;\;\;e^{\left(-b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
        (FPCore (x y z t a b)
         :precision binary64
         (let* ((t_1 (* (pow z y) x)))
           (if (<= y -1.95e+34) t_1 (if (<= y 6.8e+31) (* (exp (* (- b) a)) x) t_1))))
        double code(double x, double y, double z, double t, double a, double b) {
        	double t_1 = pow(z, y) * x;
        	double tmp;
        	if (y <= -1.95e+34) {
        		tmp = t_1;
        	} else if (y <= 6.8e+31) {
        		tmp = exp((-b * a)) * x;
        	} else {
        		tmp = t_1;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y, z, t, a, b)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8), intent (in) :: z
            real(8), intent (in) :: t
            real(8), intent (in) :: a
            real(8), intent (in) :: b
            real(8) :: t_1
            real(8) :: tmp
            t_1 = (z ** y) * x
            if (y <= (-1.95d+34)) then
                tmp = t_1
            else if (y <= 6.8d+31) then
                tmp = exp((-b * a)) * x
            else
                tmp = t_1
            end if
            code = tmp
        end function
        
        public static double code(double x, double y, double z, double t, double a, double b) {
        	double t_1 = Math.pow(z, y) * x;
        	double tmp;
        	if (y <= -1.95e+34) {
        		tmp = t_1;
        	} else if (y <= 6.8e+31) {
        		tmp = Math.exp((-b * a)) * x;
        	} else {
        		tmp = t_1;
        	}
        	return tmp;
        }
        
        def code(x, y, z, t, a, b):
        	t_1 = math.pow(z, y) * x
        	tmp = 0
        	if y <= -1.95e+34:
        		tmp = t_1
        	elif y <= 6.8e+31:
        		tmp = math.exp((-b * a)) * x
        	else:
        		tmp = t_1
        	return tmp
        
        function code(x, y, z, t, a, b)
        	t_1 = Float64((z ^ y) * x)
        	tmp = 0.0
        	if (y <= -1.95e+34)
        		tmp = t_1;
        	elseif (y <= 6.8e+31)
        		tmp = Float64(exp(Float64(Float64(-b) * a)) * x);
        	else
        		tmp = t_1;
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y, z, t, a, b)
        	t_1 = (z ^ y) * x;
        	tmp = 0.0;
        	if (y <= -1.95e+34)
        		tmp = t_1;
        	elseif (y <= 6.8e+31)
        		tmp = exp((-b * a)) * x;
        	else
        		tmp = t_1;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_, z_, t_, a_, b_] := Block[{t$95$1 = N[(N[Power[z, y], $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[y, -1.95e+34], t$95$1, If[LessEqual[y, 6.8e+31], N[(N[Exp[N[((-b) * a), $MachinePrecision]], $MachinePrecision] * x), $MachinePrecision], t$95$1]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_1 := {z}^{y} \cdot x\\
        \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\
        \;\;\;\;t\_1\\
        
        \mathbf{elif}\;y \leq 6.8 \cdot 10^{+31}:\\
        \;\;\;\;e^{\left(-b\right) \cdot a} \cdot x\\
        
        \mathbf{else}:\\
        \;\;\;\;t\_1\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if y < -1.9500000000000001e34 or 6.7999999999999996e31 < y

          1. Initial program 99.1%

            \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in a around 0

            \[\leadsto x \cdot \color{blue}{e^{y \cdot \left(\log z - t\right)}} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto x \cdot e^{\color{blue}{\left(\log z - t\right) \cdot y}} \]
            2. exp-prodN/A

              \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
            3. lower-pow.f64N/A

              \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
            4. exp-diffN/A

              \[\leadsto x \cdot {\color{blue}{\left(\frac{e^{\log z}}{e^{t}}\right)}}^{y} \]
            5. rem-exp-logN/A

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

              \[\leadsto x \cdot {\color{blue}{\left(\frac{z}{e^{t}}\right)}}^{y} \]
            7. lower-exp.f6490.5

              \[\leadsto x \cdot {\left(\frac{z}{\color{blue}{e^{t}}}\right)}^{y} \]
          5. Applied rewrites90.5%

            \[\leadsto x \cdot \color{blue}{{\left(\frac{z}{e^{t}}\right)}^{y}} \]
          6. Taylor expanded in t around 0

            \[\leadsto x \cdot {z}^{\color{blue}{y}} \]
          7. Step-by-step derivation
            1. Applied rewrites75.0%

              \[\leadsto x \cdot {z}^{\color{blue}{y}} \]

            if -1.9500000000000001e34 < y < 6.7999999999999996e31

            1. Initial program 96.6%

              \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in y around 0

              \[\leadsto x \cdot e^{\color{blue}{a \cdot \left(\log \left(1 - z\right) - b\right)}} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
              2. lower-*.f64N/A

                \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right) \cdot a}} \]
              3. lower--.f64N/A

                \[\leadsto x \cdot e^{\color{blue}{\left(\log \left(1 - z\right) - b\right)} \cdot a} \]
              4. sub-negN/A

                \[\leadsto x \cdot e^{\left(\log \color{blue}{\left(1 + \left(\mathsf{neg}\left(z\right)\right)\right)} - b\right) \cdot a} \]
              5. lower-log1p.f64N/A

                \[\leadsto x \cdot e^{\left(\color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(z\right)\right)} - b\right) \cdot a} \]
              6. lower-neg.f6481.6

                \[\leadsto x \cdot e^{\left(\mathsf{log1p}\left(\color{blue}{-z}\right) - b\right) \cdot a} \]
            5. Applied rewrites81.6%

              \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{log1p}\left(-z\right) - b\right) \cdot a}} \]
            6. Taylor expanded in z around 0

              \[\leadsto x \cdot e^{-1 \cdot \color{blue}{\left(a \cdot b\right)}} \]
            7. Step-by-step derivation
              1. Applied rewrites78.9%

                \[\leadsto x \cdot e^{\left(-b\right) \cdot \color{blue}{a}} \]
            8. Recombined 2 regimes into one program.
            9. Final simplification77.1%

              \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.95 \cdot 10^{+34}:\\ \;\;\;\;{z}^{y} \cdot x\\ \mathbf{elif}\;y \leq 6.8 \cdot 10^{+31}:\\ \;\;\;\;e^{\left(-b\right) \cdot a} \cdot x\\ \mathbf{else}:\\ \;\;\;\;{z}^{y} \cdot x\\ \end{array} \]
            10. Add Preprocessing

            Alternative 5: 51.9% accurate, 3.1× speedup?

            \[\begin{array}{l} \\ {z}^{y} \cdot x \end{array} \]
            (FPCore (x y z t a b) :precision binary64 (* (pow z y) x))
            double code(double x, double y, double z, double t, double a, double b) {
            	return pow(z, y) * x;
            }
            
            real(8) function code(x, y, z, t, a, b)
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                real(8), intent (in) :: z
                real(8), intent (in) :: t
                real(8), intent (in) :: a
                real(8), intent (in) :: b
                code = (z ** y) * x
            end function
            
            public static double code(double x, double y, double z, double t, double a, double b) {
            	return Math.pow(z, y) * x;
            }
            
            def code(x, y, z, t, a, b):
            	return math.pow(z, y) * x
            
            function code(x, y, z, t, a, b)
            	return Float64((z ^ y) * x)
            end
            
            function tmp = code(x, y, z, t, a, b)
            	tmp = (z ^ y) * x;
            end
            
            code[x_, y_, z_, t_, a_, b_] := N[(N[Power[z, y], $MachinePrecision] * x), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            {z}^{y} \cdot x
            \end{array}
            
            Derivation
            1. Initial program 97.7%

              \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in a around 0

              \[\leadsto x \cdot \color{blue}{e^{y \cdot \left(\log z - t\right)}} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto x \cdot e^{\color{blue}{\left(\log z - t\right) \cdot y}} \]
              2. exp-prodN/A

                \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
              3. lower-pow.f64N/A

                \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
              4. exp-diffN/A

                \[\leadsto x \cdot {\color{blue}{\left(\frac{e^{\log z}}{e^{t}}\right)}}^{y} \]
              5. rem-exp-logN/A

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

                \[\leadsto x \cdot {\color{blue}{\left(\frac{z}{e^{t}}\right)}}^{y} \]
              7. lower-exp.f6470.0

                \[\leadsto x \cdot {\left(\frac{z}{\color{blue}{e^{t}}}\right)}^{y} \]
            5. Applied rewrites70.0%

              \[\leadsto x \cdot \color{blue}{{\left(\frac{z}{e^{t}}\right)}^{y}} \]
            6. Taylor expanded in t around 0

              \[\leadsto x \cdot {z}^{\color{blue}{y}} \]
            7. Step-by-step derivation
              1. Applied rewrites56.7%

                \[\leadsto x \cdot {z}^{\color{blue}{y}} \]
              2. Final simplification56.7%

                \[\leadsto {z}^{y} \cdot x \]
              3. Add Preprocessing

              Alternative 6: 19.5% accurate, 54.7× speedup?

              \[\begin{array}{l} \\ 1 \cdot x \end{array} \]
              (FPCore (x y z t a b) :precision binary64 (* 1.0 x))
              double code(double x, double y, double z, double t, double a, double b) {
              	return 1.0 * x;
              }
              
              real(8) function code(x, y, z, t, a, b)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  real(8), intent (in) :: z
                  real(8), intent (in) :: t
                  real(8), intent (in) :: a
                  real(8), intent (in) :: b
                  code = 1.0d0 * x
              end function
              
              public static double code(double x, double y, double z, double t, double a, double b) {
              	return 1.0 * x;
              }
              
              def code(x, y, z, t, a, b):
              	return 1.0 * x
              
              function code(x, y, z, t, a, b)
              	return Float64(1.0 * x)
              end
              
              function tmp = code(x, y, z, t, a, b)
              	tmp = 1.0 * x;
              end
              
              code[x_, y_, z_, t_, a_, b_] := N[(1.0 * x), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              1 \cdot x
              \end{array}
              
              Derivation
              1. Initial program 97.7%

                \[x \cdot e^{y \cdot \left(\log z - t\right) + a \cdot \left(\log \left(1 - z\right) - b\right)} \]
              2. Add Preprocessing
              3. Taylor expanded in a around 0

                \[\leadsto x \cdot \color{blue}{e^{y \cdot \left(\log z - t\right)}} \]
              4. Step-by-step derivation
                1. *-commutativeN/A

                  \[\leadsto x \cdot e^{\color{blue}{\left(\log z - t\right) \cdot y}} \]
                2. exp-prodN/A

                  \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
                3. lower-pow.f64N/A

                  \[\leadsto x \cdot \color{blue}{{\left(e^{\log z - t}\right)}^{y}} \]
                4. exp-diffN/A

                  \[\leadsto x \cdot {\color{blue}{\left(\frac{e^{\log z}}{e^{t}}\right)}}^{y} \]
                5. rem-exp-logN/A

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

                  \[\leadsto x \cdot {\color{blue}{\left(\frac{z}{e^{t}}\right)}}^{y} \]
                7. lower-exp.f6470.0

                  \[\leadsto x \cdot {\left(\frac{z}{\color{blue}{e^{t}}}\right)}^{y} \]
              5. Applied rewrites70.0%

                \[\leadsto x \cdot \color{blue}{{\left(\frac{z}{e^{t}}\right)}^{y}} \]
              6. Taylor expanded in y around 0

                \[\leadsto x \cdot 1 \]
              7. Step-by-step derivation
                1. Applied rewrites21.1%

                  \[\leadsto x \cdot 1 \]
                2. Final simplification21.1%

                  \[\leadsto 1 \cdot x \]
                3. Add Preprocessing

                Reproduce

                ?
                herbie shell --seed 2024294 
                (FPCore (x y z t a b)
                  :name "Numeric.SpecFunctions:incompleteBetaApprox from math-functions-0.1.5.2, B"
                  :precision binary64
                  (* x (exp (+ (* y (- (log z) t)) (* a (- (log (- 1.0 z)) b))))))