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

Percentage Accurate: 96.4% → 99.3%
Time: 8.3s
Alternatives: 7
Speedup: 1.5×

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 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: 96.4% 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: 99.3% accurate, 1.5× speedup?

\[\begin{array}{l} \\ x \cdot e^{\mathsf{fma}\left(-a, z + b, \left(\log z - t\right) \cdot y\right)} \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (* x (exp (fma (- a) (+ z b) (* (- (log z) t) y)))))
double code(double x, double y, double z, double t, double a, double b) {
	return x * exp(fma(-a, (z + b), ((log(z) - t) * y)));
}
function code(x, y, z, t, a, b)
	return Float64(x * exp(fma(Float64(-a), Float64(z + b), Float64(Float64(log(z) - t) * y))))
end
code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[((-a) * N[(z + b), $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot e^{\mathsf{fma}\left(-a, z + b, \left(\log z - t\right) \cdot y\right)}
\end{array}
Derivation
  1. Initial program 96.5%

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

    \[\leadsto x \cdot e^{\color{blue}{-1 \cdot \left(a \cdot b\right) + \left(-1 \cdot \left(a \cdot z\right) + y \cdot \left(\log z - t\right)\right)}} \]
  4. Step-by-step derivation
    1. associate-+r+N/A

      \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot b\right) + -1 \cdot \left(a \cdot z\right)\right) + y \cdot \left(\log z - t\right)}} \]
    2. +-commutativeN/A

      \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot z\right) + -1 \cdot \left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
    3. associate-*r*N/A

      \[\leadsto x \cdot e^{\left(\color{blue}{\left(-1 \cdot a\right) \cdot z} + -1 \cdot \left(a \cdot b\right)\right) + y \cdot \left(\log z - t\right)} \]
    4. associate-*r*N/A

      \[\leadsto x \cdot e^{\left(\left(-1 \cdot a\right) \cdot z + \color{blue}{\left(-1 \cdot a\right) \cdot b}\right) + y \cdot \left(\log z - t\right)} \]
    5. distribute-lft-outN/A

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

      \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-1 \cdot a, z + b, y \cdot \left(\log z - t\right)\right)}} \]
    7. mul-1-negN/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(a\right)}, z + b, y \cdot \left(\log z - t\right)\right)} \]
    8. lower-neg.f64N/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-a}, z + b, y \cdot \left(\log z - t\right)\right)} \]
    9. lower-+.f64N/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, \color{blue}{z + b}, y \cdot \left(\log z - t\right)\right)} \]
    10. *-commutativeN/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
    11. lower-*.f64N/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
    12. lower--.f64N/A

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
    13. lower-log.f64100.0

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
  5. Applied rewrites100.0%

    \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-a, z + b, \left(\log z - t\right) \cdot y\right)}} \]
  6. Add Preprocessing

Alternative 2: 95.6% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -260 \lor \neg \left(t \leq 1.08 \cdot 10^{-114}\right):\\ \;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \log z \cdot y\right)}\\ \end{array} \end{array} \]
(FPCore (x y z t a b)
 :precision binary64
 (if (or (<= t -260.0) (not (<= t 1.08e-114)))
   (* x (exp (fma (- b) a (* (- t) y))))
   (* x (exp (fma (- b) a (* (log z) y))))))
double code(double x, double y, double z, double t, double a, double b) {
	double tmp;
	if ((t <= -260.0) || !(t <= 1.08e-114)) {
		tmp = x * exp(fma(-b, a, (-t * y)));
	} else {
		tmp = x * exp(fma(-b, a, (log(z) * y)));
	}
	return tmp;
}
function code(x, y, z, t, a, b)
	tmp = 0.0
	if ((t <= -260.0) || !(t <= 1.08e-114))
		tmp = Float64(x * exp(fma(Float64(-b), a, Float64(Float64(-t) * y))));
	else
		tmp = Float64(x * exp(fma(Float64(-b), a, Float64(log(z) * y))));
	end
	return tmp
end
code[x_, y_, z_, t_, a_, b_] := If[Or[LessEqual[t, -260.0], N[Not[LessEqual[t, 1.08e-114]], $MachinePrecision]], N[(x * N[Exp[N[((-b) * a + N[((-t) * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(x * N[Exp[N[((-b) * a + N[(N[Log[z], $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq -260 \lor \neg \left(t \leq 1.08 \cdot 10^{-114}\right):\\
\;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)}\\

\mathbf{else}:\\
\;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \log z \cdot y\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -260 or 1.08e-114 < t

    1. Initial program 95.7%

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

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

        \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
      2. *-commutativeN/A

        \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
      3. distribute-lft-neg-inN/A

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

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

        \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
      6. *-commutativeN/A

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
      7. lower-*.f64N/A

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
      8. lower--.f64N/A

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
      9. lower-log.f6497.2

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
    5. Applied rewrites97.2%

      \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-b, a, \left(\log z - t\right) \cdot y\right)}} \]
    6. Taylor expanded in t around inf

      \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(-1 \cdot t\right) \cdot y\right)} \]
    7. Step-by-step derivation
      1. Applied rewrites96.8%

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)} \]

      if -260 < t < 1.08e-114

      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 z around 0

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

          \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
        2. *-commutativeN/A

          \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
        3. distribute-lft-neg-inN/A

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

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

          \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
        6. *-commutativeN/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
        7. lower-*.f64N/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
        8. lower--.f64N/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
        9. lower-log.f6496.7

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
      5. Applied rewrites96.7%

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

        \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \log z \cdot y\right)} \]
      7. Step-by-step derivation
        1. Applied rewrites96.7%

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \log z \cdot y\right)} \]
      8. Recombined 2 regimes into one program.
      9. Final simplification96.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -260 \lor \neg \left(t \leq 1.08 \cdot 10^{-114}\right):\\ \;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\mathsf{fma}\left(-b, a, \log z \cdot y\right)}\\ \end{array} \]
      10. Add Preprocessing

      Alternative 3: 96.2% accurate, 1.5× speedup?

      \[\begin{array}{l} \\ x \cdot e^{\mathsf{fma}\left(-b, a, \left(\log z - t\right) \cdot y\right)} \end{array} \]
      (FPCore (x y z t a b)
       :precision binary64
       (* x (exp (fma (- b) a (* (- (log z) t) y)))))
      double code(double x, double y, double z, double t, double a, double b) {
      	return x * exp(fma(-b, a, ((log(z) - t) * y)));
      }
      
      function code(x, y, z, t, a, b)
      	return Float64(x * exp(fma(Float64(-b), a, Float64(Float64(log(z) - t) * y))))
      end
      
      code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[((-b) * a + N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      x \cdot e^{\mathsf{fma}\left(-b, a, \left(\log z - t\right) \cdot y\right)}
      \end{array}
      
      Derivation
      1. Initial program 96.5%

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

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

          \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
        2. *-commutativeN/A

          \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
        3. distribute-lft-neg-inN/A

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

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

          \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
        6. *-commutativeN/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
        7. lower-*.f64N/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
        8. lower--.f64N/A

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
        9. lower-log.f6497.0

          \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
      5. Applied rewrites97.0%

        \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-b, a, \left(\log z - t\right) \cdot y\right)}} \]
      6. Add Preprocessing

      Alternative 4: 72.7% accurate, 2.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -580 \lor \neg \left(t \leq 2.6 \cdot 10^{+54}\right):\\ \;\;\;\;x \cdot e^{\left(-y\right) \cdot t}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\ \end{array} \end{array} \]
      (FPCore (x y z t a b)
       :precision binary64
       (if (or (<= t -580.0) (not (<= t 2.6e+54)))
         (* x (exp (* (- y) t)))
         (* x (exp (* (- b) a)))))
      double code(double x, double y, double z, double t, double a, double b) {
      	double tmp;
      	if ((t <= -580.0) || !(t <= 2.6e+54)) {
      		tmp = x * exp((-y * t));
      	} else {
      		tmp = x * exp((-b * a));
      	}
      	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) :: tmp
          if ((t <= (-580.0d0)) .or. (.not. (t <= 2.6d+54))) then
              tmp = x * exp((-y * t))
          else
              tmp = x * exp((-b * a))
          end if
          code = tmp
      end function
      
      public static double code(double x, double y, double z, double t, double a, double b) {
      	double tmp;
      	if ((t <= -580.0) || !(t <= 2.6e+54)) {
      		tmp = x * Math.exp((-y * t));
      	} else {
      		tmp = x * Math.exp((-b * a));
      	}
      	return tmp;
      }
      
      def code(x, y, z, t, a, b):
      	tmp = 0
      	if (t <= -580.0) or not (t <= 2.6e+54):
      		tmp = x * math.exp((-y * t))
      	else:
      		tmp = x * math.exp((-b * a))
      	return tmp
      
      function code(x, y, z, t, a, b)
      	tmp = 0.0
      	if ((t <= -580.0) || !(t <= 2.6e+54))
      		tmp = Float64(x * exp(Float64(Float64(-y) * t)));
      	else
      		tmp = Float64(x * exp(Float64(Float64(-b) * a)));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y, z, t, a, b)
      	tmp = 0.0;
      	if ((t <= -580.0) || ~((t <= 2.6e+54)))
      		tmp = x * exp((-y * t));
      	else
      		tmp = x * exp((-b * a));
      	end
      	tmp_2 = tmp;
      end
      
      code[x_, y_, z_, t_, a_, b_] := If[Or[LessEqual[t, -580.0], N[Not[LessEqual[t, 2.6e+54]], $MachinePrecision]], N[(x * N[Exp[N[((-y) * t), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(x * N[Exp[N[((-b) * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;t \leq -580 \lor \neg \left(t \leq 2.6 \cdot 10^{+54}\right):\\
      \;\;\;\;x \cdot e^{\left(-y\right) \cdot t}\\
      
      \mathbf{else}:\\
      \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if t < -580 or 2.60000000000000007e54 < t

        1. Initial program 95.4%

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

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

            \[\leadsto x \cdot e^{\color{blue}{\mathsf{neg}\left(t \cdot y\right)}} \]
          2. *-commutativeN/A

            \[\leadsto x \cdot e^{\mathsf{neg}\left(\color{blue}{y \cdot t}\right)} \]
          3. distribute-lft-neg-inN/A

            \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(y\right)\right) \cdot t}} \]
          4. lower-*.f64N/A

            \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(y\right)\right) \cdot t}} \]
          5. lower-neg.f6482.2

            \[\leadsto x \cdot e^{\color{blue}{\left(-y\right)} \cdot t} \]
        5. Applied rewrites82.2%

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

        if -580 < t < 2.60000000000000007e54

        1. Initial program 97.4%

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

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

            \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
          2. *-commutativeN/A

            \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
          3. distribute-lft-neg-inN/A

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

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

            \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
          6. *-commutativeN/A

            \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
          7. lower-*.f64N/A

            \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
          8. lower--.f64N/A

            \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
          9. lower-log.f6496.7

            \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
        5. Applied rewrites96.7%

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

          \[\leadsto x \cdot e^{-1 \cdot \color{blue}{\left(a \cdot b\right)}} \]
        7. Step-by-step derivation
          1. Applied rewrites67.1%

            \[\leadsto x \cdot e^{\left(-b\right) \cdot \color{blue}{a}} \]
        8. Recombined 2 regimes into one program.
        9. Final simplification73.5%

          \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -580 \lor \neg \left(t \leq 2.6 \cdot 10^{+54}\right):\\ \;\;\;\;x \cdot e^{\left(-y\right) \cdot t}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\ \end{array} \]
        10. Add Preprocessing

        Alternative 5: 61.8% accurate, 2.6× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.05 \cdot 10^{-101} \lor \neg \left(b \leq 6.5 \cdot 10^{-108}\right):\\ \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\left(-z\right) \cdot a}\\ \end{array} \end{array} \]
        (FPCore (x y z t a b)
         :precision binary64
         (if (or (<= b -1.05e-101) (not (<= b 6.5e-108)))
           (* x (exp (* (- b) a)))
           (* x (exp (* (- z) a)))))
        double code(double x, double y, double z, double t, double a, double b) {
        	double tmp;
        	if ((b <= -1.05e-101) || !(b <= 6.5e-108)) {
        		tmp = x * exp((-b * a));
        	} else {
        		tmp = x * exp((-z * a));
        	}
        	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) :: tmp
            if ((b <= (-1.05d-101)) .or. (.not. (b <= 6.5d-108))) then
                tmp = x * exp((-b * a))
            else
                tmp = x * exp((-z * a))
            end if
            code = tmp
        end function
        
        public static double code(double x, double y, double z, double t, double a, double b) {
        	double tmp;
        	if ((b <= -1.05e-101) || !(b <= 6.5e-108)) {
        		tmp = x * Math.exp((-b * a));
        	} else {
        		tmp = x * Math.exp((-z * a));
        	}
        	return tmp;
        }
        
        def code(x, y, z, t, a, b):
        	tmp = 0
        	if (b <= -1.05e-101) or not (b <= 6.5e-108):
        		tmp = x * math.exp((-b * a))
        	else:
        		tmp = x * math.exp((-z * a))
        	return tmp
        
        function code(x, y, z, t, a, b)
        	tmp = 0.0
        	if ((b <= -1.05e-101) || !(b <= 6.5e-108))
        		tmp = Float64(x * exp(Float64(Float64(-b) * a)));
        	else
        		tmp = Float64(x * exp(Float64(Float64(-z) * a)));
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y, z, t, a, b)
        	tmp = 0.0;
        	if ((b <= -1.05e-101) || ~((b <= 6.5e-108)))
        		tmp = x * exp((-b * a));
        	else
        		tmp = x * exp((-z * a));
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_, z_, t_, a_, b_] := If[Or[LessEqual[b, -1.05e-101], N[Not[LessEqual[b, 6.5e-108]], $MachinePrecision]], N[(x * N[Exp[N[((-b) * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(x * N[Exp[N[((-z) * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;b \leq -1.05 \cdot 10^{-101} \lor \neg \left(b \leq 6.5 \cdot 10^{-108}\right):\\
        \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\
        
        \mathbf{else}:\\
        \;\;\;\;x \cdot e^{\left(-z\right) \cdot a}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if b < -1.05000000000000008e-101 or 6.5000000000000002e-108 < b

          1. Initial program 98.3%

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

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

              \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
            2. *-commutativeN/A

              \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
            3. distribute-lft-neg-inN/A

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

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

              \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
            6. *-commutativeN/A

              \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
            7. lower-*.f64N/A

              \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
            8. lower--.f64N/A

              \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
            9. lower-log.f6499.4

              \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
          5. Applied rewrites99.4%

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

            \[\leadsto x \cdot e^{-1 \cdot \color{blue}{\left(a \cdot b\right)}} \]
          7. Step-by-step derivation
            1. Applied rewrites69.9%

              \[\leadsto x \cdot e^{\left(-b\right) \cdot \color{blue}{a}} \]

            if -1.05000000000000008e-101 < b < 6.5000000000000002e-108

            1. Initial program 92.7%

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

              \[\leadsto x \cdot e^{\color{blue}{-1 \cdot \left(a \cdot b\right) + \left(-1 \cdot \left(a \cdot z\right) + y \cdot \left(\log z - t\right)\right)}} \]
            4. Step-by-step derivation
              1. associate-+r+N/A

                \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot b\right) + -1 \cdot \left(a \cdot z\right)\right) + y \cdot \left(\log z - t\right)}} \]
              2. +-commutativeN/A

                \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot z\right) + -1 \cdot \left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
              3. associate-*r*N/A

                \[\leadsto x \cdot e^{\left(\color{blue}{\left(-1 \cdot a\right) \cdot z} + -1 \cdot \left(a \cdot b\right)\right) + y \cdot \left(\log z - t\right)} \]
              4. associate-*r*N/A

                \[\leadsto x \cdot e^{\left(\left(-1 \cdot a\right) \cdot z + \color{blue}{\left(-1 \cdot a\right) \cdot b}\right) + y \cdot \left(\log z - t\right)} \]
              5. distribute-lft-outN/A

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

                \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-1 \cdot a, z + b, y \cdot \left(\log z - t\right)\right)}} \]
              7. mul-1-negN/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(a\right)}, z + b, y \cdot \left(\log z - t\right)\right)} \]
              8. lower-neg.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-a}, z + b, y \cdot \left(\log z - t\right)\right)} \]
              9. lower-+.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, \color{blue}{z + b}, y \cdot \left(\log z - t\right)\right)} \]
              10. *-commutativeN/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
              11. lower-*.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
              12. lower--.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
              13. lower-log.f64100.0

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
            5. Applied rewrites100.0%

              \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-a, z + b, \left(\log z - t\right) \cdot y\right)}} \]
            6. Taylor expanded in z around inf

              \[\leadsto x \cdot e^{-1 \cdot \color{blue}{\left(a \cdot z\right)}} \]
            7. Step-by-step derivation
              1. Applied rewrites47.2%

                \[\leadsto x \cdot e^{\left(-z\right) \cdot \color{blue}{a}} \]
            8. Recombined 2 regimes into one program.
            9. Final simplification62.8%

              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.05 \cdot 10^{-101} \lor \neg \left(b \leq 6.5 \cdot 10^{-108}\right):\\ \;\;\;\;x \cdot e^{\left(-b\right) \cdot a}\\ \mathbf{else}:\\ \;\;\;\;x \cdot e^{\left(-z\right) \cdot a}\\ \end{array} \]
            10. Add Preprocessing

            Alternative 6: 84.4% accurate, 2.7× speedup?

            \[\begin{array}{l} \\ x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)} \end{array} \]
            (FPCore (x y z t a b)
             :precision binary64
             (* x (exp (fma (- b) a (* (- t) y)))))
            double code(double x, double y, double z, double t, double a, double b) {
            	return x * exp(fma(-b, a, (-t * y)));
            }
            
            function code(x, y, z, t, a, b)
            	return Float64(x * exp(fma(Float64(-b), a, Float64(Float64(-t) * y))))
            end
            
            code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[((-b) * a + N[((-t) * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)}
            \end{array}
            
            Derivation
            1. Initial program 96.5%

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

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

                \[\leadsto x \cdot e^{\color{blue}{\left(\mathsf{neg}\left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
              2. *-commutativeN/A

                \[\leadsto x \cdot e^{\left(\mathsf{neg}\left(\color{blue}{b \cdot a}\right)\right) + y \cdot \left(\log z - t\right)} \]
              3. distribute-lft-neg-inN/A

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

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

                \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-b}, a, y \cdot \left(\log z - t\right)\right)} \]
              6. *-commutativeN/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
              7. lower-*.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
              8. lower--.f64N/A

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
              9. lower-log.f6497.0

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
            5. Applied rewrites97.0%

              \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-b, a, \left(\log z - t\right) \cdot y\right)}} \]
            6. Taylor expanded in t around inf

              \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(-1 \cdot t\right) \cdot y\right)} \]
            7. Step-by-step derivation
              1. Applied rewrites82.1%

                \[\leadsto x \cdot e^{\mathsf{fma}\left(-b, a, \left(-t\right) \cdot y\right)} \]
              2. Add Preprocessing

              Alternative 7: 33.8% accurate, 2.9× speedup?

              \[\begin{array}{l} \\ x \cdot e^{\left(-z\right) \cdot a} \end{array} \]
              (FPCore (x y z t a b) :precision binary64 (* x (exp (* (- z) a))))
              double code(double x, double y, double z, double t, double a, double b) {
              	return x * exp((-z * a));
              }
              
              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((-z * a))
              end function
              
              public static double code(double x, double y, double z, double t, double a, double b) {
              	return x * Math.exp((-z * a));
              }
              
              def code(x, y, z, t, a, b):
              	return x * math.exp((-z * a))
              
              function code(x, y, z, t, a, b)
              	return Float64(x * exp(Float64(Float64(-z) * a)))
              end
              
              function tmp = code(x, y, z, t, a, b)
              	tmp = x * exp((-z * a));
              end
              
              code[x_, y_, z_, t_, a_, b_] := N[(x * N[Exp[N[((-z) * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              x \cdot e^{\left(-z\right) \cdot a}
              \end{array}
              
              Derivation
              1. Initial program 96.5%

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

                \[\leadsto x \cdot e^{\color{blue}{-1 \cdot \left(a \cdot b\right) + \left(-1 \cdot \left(a \cdot z\right) + y \cdot \left(\log z - t\right)\right)}} \]
              4. Step-by-step derivation
                1. associate-+r+N/A

                  \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot b\right) + -1 \cdot \left(a \cdot z\right)\right) + y \cdot \left(\log z - t\right)}} \]
                2. +-commutativeN/A

                  \[\leadsto x \cdot e^{\color{blue}{\left(-1 \cdot \left(a \cdot z\right) + -1 \cdot \left(a \cdot b\right)\right)} + y \cdot \left(\log z - t\right)} \]
                3. associate-*r*N/A

                  \[\leadsto x \cdot e^{\left(\color{blue}{\left(-1 \cdot a\right) \cdot z} + -1 \cdot \left(a \cdot b\right)\right) + y \cdot \left(\log z - t\right)} \]
                4. associate-*r*N/A

                  \[\leadsto x \cdot e^{\left(\left(-1 \cdot a\right) \cdot z + \color{blue}{\left(-1 \cdot a\right) \cdot b}\right) + y \cdot \left(\log z - t\right)} \]
                5. distribute-lft-outN/A

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

                  \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-1 \cdot a, z + b, y \cdot \left(\log z - t\right)\right)}} \]
                7. mul-1-negN/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(a\right)}, z + b, y \cdot \left(\log z - t\right)\right)} \]
                8. lower-neg.f64N/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(\color{blue}{-a}, z + b, y \cdot \left(\log z - t\right)\right)} \]
                9. lower-+.f64N/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, \color{blue}{z + b}, y \cdot \left(\log z - t\right)\right)} \]
                10. *-commutativeN/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
                11. lower-*.f64N/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right) \cdot y}\right)} \]
                12. lower--.f64N/A

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \color{blue}{\left(\log z - t\right)} \cdot y\right)} \]
                13. lower-log.f64100.0

                  \[\leadsto x \cdot e^{\mathsf{fma}\left(-a, z + b, \left(\color{blue}{\log z} - t\right) \cdot y\right)} \]
              5. Applied rewrites100.0%

                \[\leadsto x \cdot e^{\color{blue}{\mathsf{fma}\left(-a, z + b, \left(\log z - t\right) \cdot y\right)}} \]
              6. Taylor expanded in z around inf

                \[\leadsto x \cdot e^{-1 \cdot \color{blue}{\left(a \cdot z\right)}} \]
              7. Step-by-step derivation
                1. Applied rewrites34.4%

                  \[\leadsto x \cdot e^{\left(-z\right) \cdot \color{blue}{a}} \]
                2. Add Preprocessing

                Reproduce

                ?
                herbie shell --seed 2024326 
                (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))))))