Harley's example

Percentage Accurate: 90.9% → 94.6%
Time: 48.5s
Alternatives: 3
Speedup: 896.0×

Specification

?
\[0 < c\_p \land 0 < c\_n\]
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{1 + e^{-t}}\\ t_2 := \frac{1}{1 + e^{-s}}\\ \frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}} \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
   (/
    (* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
    (* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + exp(-t));
	double t_2 = 1.0 / (1.0 + exp(-s));
	return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 1.0d0 / (1.0d0 + exp(-t))
    t_2 = 1.0d0 / (1.0d0 + exp(-s))
    code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + Math.exp(-t));
	double t_2 = 1.0 / (1.0 + Math.exp(-s));
	return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s):
	t_1 = 1.0 / (1.0 + math.exp(-t))
	t_2 = 1.0 / (1.0 + math.exp(-s))
	return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s)
	t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t))))
	t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s))))
	return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n)))
end
function tmp = code(c_p, c_n, t, s)
	t_1 = 1.0 / (1.0 + exp(-t));
	t_2 = 1.0 / (1.0 + exp(-s));
	tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n));
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\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 3 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: 90.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{1 + e^{-t}}\\ t_2 := \frac{1}{1 + e^{-s}}\\ \frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}} \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
   (/
    (* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
    (* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + exp(-t));
	double t_2 = 1.0 / (1.0 + exp(-s));
	return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 1.0d0 / (1.0d0 + exp(-t))
    t_2 = 1.0d0 / (1.0d0 + exp(-s))
    code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + Math.exp(-t));
	double t_2 = 1.0 / (1.0 + Math.exp(-s));
	return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s):
	t_1 = 1.0 / (1.0 + math.exp(-t))
	t_2 = 1.0 / (1.0 + math.exp(-s))
	return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s)
	t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t))))
	t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s))))
	return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n)))
end
function tmp = code(c_p, c_n, t, s)
	t_1 = 1.0 / (1.0 + exp(-t));
	t_2 = 1.0 / (1.0 + exp(-s));
	tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n));
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}

Alternative 1: 94.6% accurate, 896.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 1.0)
double code(double c_p, double c_n, double t, double s) {
	return 1.0;
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    code = 1.0d0
end function
public static double code(double c_p, double c_n, double t, double s) {
	return 1.0;
}
def code(c_p, c_n, t, s):
	return 1.0
function code(c_p, c_n, t, s)
	return 1.0
end
function tmp = code(c_p, c_n, t, s)
	tmp = 1.0;
end
code[c$95$p_, c$95$n_, t_, s_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 92.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Taylor expanded in t around 0

    \[\leadsto \frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p} \cdot {\color{blue}{\frac{1}{2}}}^{c\_n}} \]
  4. Step-by-step derivation
    1. Simplified93.0%

      \[\leadsto \frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\color{blue}{0.5}}^{c\_n}} \]
    2. Taylor expanded in s around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + e^{\mathsf{neg}\left(t\right)}\right)} \]
    3. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(e^{\mathsf{neg}\left(t\right)} + 1\right)} \]
      2. distribute-lft-inN/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot e^{\mathsf{neg}\left(t\right)} + \frac{1}{2} \cdot 1} \]
      3. metadata-evalN/A

        \[\leadsto \frac{1}{2} \cdot e^{\mathsf{neg}\left(t\right)} + \color{blue}{\frac{1}{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, e^{\mathsf{neg}\left(t\right)}, \frac{1}{2}\right)} \]
      5. neg-mul-1N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, e^{\color{blue}{-1 \cdot t}}, \frac{1}{2}\right) \]
      6. lower-exp.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, \color{blue}{e^{-1 \cdot t}}, \frac{1}{2}\right) \]
      7. neg-mul-1N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, e^{\color{blue}{\mathsf{neg}\left(t\right)}}, \frac{1}{2}\right) \]
      8. lower-neg.f6495.7

        \[\leadsto \mathsf{fma}\left(0.5, e^{\color{blue}{-t}}, 0.5\right) \]
    4. Simplified95.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, e^{-t}, 0.5\right)} \]
    5. Taylor expanded in t around 0

      \[\leadsto \color{blue}{1} \]
    6. Step-by-step derivation
      1. Simplified98.3%

        \[\leadsto \color{blue}{1} \]
      2. Add Preprocessing

      Alternative 2: 14.1% accurate, 896.0× speedup?

      \[\begin{array}{l} \\ 0.015625 \end{array} \]
      (FPCore (c_p c_n t s) :precision binary64 0.015625)
      double code(double c_p, double c_n, double t, double s) {
      	return 0.015625;
      }
      
      real(8) function code(c_p, c_n, t, s)
          real(8), intent (in) :: c_p
          real(8), intent (in) :: c_n
          real(8), intent (in) :: t
          real(8), intent (in) :: s
          code = 0.015625d0
      end function
      
      public static double code(double c_p, double c_n, double t, double s) {
      	return 0.015625;
      }
      
      def code(c_p, c_n, t, s):
      	return 0.015625
      
      function code(c_p, c_n, t, s)
      	return 0.015625
      end
      
      function tmp = code(c_p, c_n, t, s)
      	tmp = 0.015625;
      end
      
      code[c$95$p_, c$95$n_, t_, s_] := 0.015625
      
      \begin{array}{l}
      
      \\
      0.015625
      \end{array}
      
      Derivation
      1. Initial program 92.6%

        \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
      2. Add Preprocessing
      3. Taylor expanded in t around 0

        \[\leadsto \color{blue}{8 \cdot \frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
      4. Step-by-step derivation
        1. associate-*r/N/A

          \[\leadsto \color{blue}{\frac{8 \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
        2. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{8 \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
        3. *-commutativeN/A

          \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        4. lower-*.f64N/A

          \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        5. lower-pow.f64N/A

          \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        6. sub-negN/A

          \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        7. lower-+.f64N/A

          \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        8. distribute-neg-fracN/A

          \[\leadsto \frac{{\left(1 + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        9. metadata-evalN/A

          \[\leadsto \frac{{\left(1 + \frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        10. lower-/.f64N/A

          \[\leadsto \frac{{\left(1 + \color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        11. lower-+.f64N/A

          \[\leadsto \frac{{\left(1 + \frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        12. lower-exp.f64N/A

          \[\leadsto \frac{{\left(1 + \frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        13. lower-neg.f64N/A

          \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
        14. lower-+.f64N/A

          \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
        15. lower-exp.f64N/A

          \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}} \]
      5. Simplified96.3%

        \[\leadsto \color{blue}{\frac{{\left(1 + \frac{-1}{1 + e^{-s}}\right)}^{2} \cdot 8}{1 + e^{-s}}} \]
      6. Taylor expanded in s around 0

        \[\leadsto \color{blue}{\frac{1}{64}} \]
      7. Step-by-step derivation
        1. Simplified14.5%

          \[\leadsto \color{blue}{0.015625} \]
        2. Add Preprocessing

        Alternative 3: 13.8% accurate, 896.0× speedup?

        \[\begin{array}{l} \\ 0.0078125 \end{array} \]
        (FPCore (c_p c_n t s) :precision binary64 0.0078125)
        double code(double c_p, double c_n, double t, double s) {
        	return 0.0078125;
        }
        
        real(8) function code(c_p, c_n, t, s)
            real(8), intent (in) :: c_p
            real(8), intent (in) :: c_n
            real(8), intent (in) :: t
            real(8), intent (in) :: s
            code = 0.0078125d0
        end function
        
        public static double code(double c_p, double c_n, double t, double s) {
        	return 0.0078125;
        }
        
        def code(c_p, c_n, t, s):
        	return 0.0078125
        
        function code(c_p, c_n, t, s)
        	return 0.0078125
        end
        
        function tmp = code(c_p, c_n, t, s)
        	tmp = 0.0078125;
        end
        
        code[c$95$p_, c$95$n_, t_, s_] := 0.0078125
        
        \begin{array}{l}
        
        \\
        0.0078125
        \end{array}
        
        Derivation
        1. Initial program 92.6%

          \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
        2. Add Preprocessing
        3. Taylor expanded in t around 0

          \[\leadsto \color{blue}{8 \cdot \frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
        4. Step-by-step derivation
          1. associate-*r/N/A

            \[\leadsto \color{blue}{\frac{8 \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
          2. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{8 \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
          3. *-commutativeN/A

            \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          4. lower-*.f64N/A

            \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          5. lower-pow.f64N/A

            \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          6. sub-negN/A

            \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          7. lower-+.f64N/A

            \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          8. distribute-neg-fracN/A

            \[\leadsto \frac{{\left(1 + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          9. metadata-evalN/A

            \[\leadsto \frac{{\left(1 + \frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          10. lower-/.f64N/A

            \[\leadsto \frac{{\left(1 + \color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          11. lower-+.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          12. lower-exp.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          13. lower-neg.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          14. lower-+.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}} \]
          15. lower-exp.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}} \]
        5. Simplified96.3%

          \[\leadsto \color{blue}{\frac{{\left(1 + \frac{-1}{1 + e^{-s}}\right)}^{2} \cdot 8}{1 + e^{-s}}} \]
        6. Step-by-step derivation
          1. lift-neg.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          2. lift-exp.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          3. lift-+.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          4. lift-/.f64N/A

            \[\leadsto \frac{{\left(1 + \color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          5. lift-+.f64N/A

            \[\leadsto \frac{{\color{blue}{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}^{2} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          6. lift-pow.f64N/A

            \[\leadsto \frac{\color{blue}{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2}} \cdot 8}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          7. lift-*.f64N/A

            \[\leadsto \frac{\color{blue}{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}}{1 + e^{\mathsf{neg}\left(s\right)}} \]
          8. lift-neg.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}} \]
          9. lift-exp.f64N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}} \]
          10. flip-+N/A

            \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{\color{blue}{\frac{1 \cdot 1 - e^{\mathsf{neg}\left(s\right)} \cdot e^{\mathsf{neg}\left(s\right)}}{1 - e^{\mathsf{neg}\left(s\right)}}}} \]
          11. associate-/r/N/A

            \[\leadsto \color{blue}{\frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{2} \cdot 8}{1 \cdot 1 - e^{\mathsf{neg}\left(s\right)} \cdot e^{\mathsf{neg}\left(s\right)}} \cdot \left(1 - e^{\mathsf{neg}\left(s\right)}\right)} \]
        7. Applied egg-rr4.7%

          \[\leadsto \color{blue}{\frac{{\left(1 + \frac{-1}{1 + e^{-s}}\right)}^{2} \cdot 8}{1 - e^{\left(-s\right) - s}} \cdot \left(1 - e^{-s}\right)} \]
        8. Taylor expanded in s around 0

          \[\leadsto \color{blue}{\frac{1}{128}} \]
        9. Step-by-step derivation
          1. Simplified14.2%

            \[\leadsto \color{blue}{0.0078125} \]
          2. Add Preprocessing

          Developer Target 1: 96.3% accurate, 1.4× speedup?

          \[\begin{array}{l} \\ {\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n} \end{array} \]
          (FPCore (c_p c_n t s)
           :precision binary64
           (*
            (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p)
            (pow (/ (+ 1.0 (exp t)) (+ 1.0 (exp s))) c_n)))
          double code(double c_p, double c_n, double t, double s) {
          	return pow(((1.0 + exp(-t)) / (1.0 + exp(-s))), c_p) * pow(((1.0 + exp(t)) / (1.0 + exp(s))), c_n);
          }
          
          real(8) function code(c_p, c_n, t, s)
              real(8), intent (in) :: c_p
              real(8), intent (in) :: c_n
              real(8), intent (in) :: t
              real(8), intent (in) :: s
              code = (((1.0d0 + exp(-t)) / (1.0d0 + exp(-s))) ** c_p) * (((1.0d0 + exp(t)) / (1.0d0 + exp(s))) ** c_n)
          end function
          
          public static double code(double c_p, double c_n, double t, double s) {
          	return Math.pow(((1.0 + Math.exp(-t)) / (1.0 + Math.exp(-s))), c_p) * Math.pow(((1.0 + Math.exp(t)) / (1.0 + Math.exp(s))), c_n);
          }
          
          def code(c_p, c_n, t, s):
          	return math.pow(((1.0 + math.exp(-t)) / (1.0 + math.exp(-s))), c_p) * math.pow(((1.0 + math.exp(t)) / (1.0 + math.exp(s))), c_n)
          
          function code(c_p, c_n, t, s)
          	return Float64((Float64(Float64(1.0 + exp(Float64(-t))) / Float64(1.0 + exp(Float64(-s)))) ^ c_p) * (Float64(Float64(1.0 + exp(t)) / Float64(1.0 + exp(s))) ^ c_n))
          end
          
          function tmp = code(c_p, c_n, t, s)
          	tmp = (((1.0 + exp(-t)) / (1.0 + exp(-s))) ^ c_p) * (((1.0 + exp(t)) / (1.0 + exp(s))) ^ c_n);
          end
          
          code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[N[(N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(N[(1.0 + N[Exp[t], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[s], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          {\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n}
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024214 
          (FPCore (c_p c_n t s)
            :name "Harley's example"
            :precision binary64
            :pre (and (< 0.0 c_p) (< 0.0 c_n))
          
            :alt
            (! :herbie-platform default (* (pow (/ (+ 1 (exp (- t))) (+ 1 (exp (- s)))) c_p) (pow (/ (+ 1 (exp t)) (+ 1 (exp s))) c_n)))
          
            (/ (* (pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- s))))) c_n)) (* (pow (/ 1.0 (+ 1.0 (exp (- t)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- t))))) c_n))))