Harley's example

Percentage Accurate: 90.7% → 95.6%
Time: 48.7s
Alternatives: 4
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 4 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: 90.7% 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: 95.6% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{-s} + 1\\ \mathbf{if}\;-s \leq -1 \cdot 10^{-286}:\\ \;\;\;\;\frac{{\left(1 - {t\_1}^{-1}\right)}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;{\left(t\_1 \cdot 0.5\right)}^{\left(-c\_p\right)}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (+ (exp (- s)) 1.0)))
   (if (<= (- s) -1e-286)
     (/
      (pow (- 1.0 (pow t_1 -1.0)) c_n)
      (pow (- 1.0 (pow (+ (exp (- t)) 1.0) -1.0)) c_n))
     (pow (* t_1 0.5) (- c_p)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = exp(-s) + 1.0;
	double tmp;
	if (-s <= -1e-286) {
		tmp = pow((1.0 - pow(t_1, -1.0)), c_n) / pow((1.0 - pow((exp(-t) + 1.0), -1.0)), c_n);
	} else {
		tmp = pow((t_1 * 0.5), -c_p);
	}
	return tmp;
}
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) :: tmp
    t_1 = exp(-s) + 1.0d0
    if (-s <= (-1d-286)) then
        tmp = ((1.0d0 - (t_1 ** (-1.0d0))) ** c_n) / ((1.0d0 - ((exp(-t) + 1.0d0) ** (-1.0d0))) ** c_n)
    else
        tmp = (t_1 * 0.5d0) ** -c_p
    end if
    code = tmp
end function
public static double code(double c_p, double c_n, double t, double s) {
	double t_1 = Math.exp(-s) + 1.0;
	double tmp;
	if (-s <= -1e-286) {
		tmp = Math.pow((1.0 - Math.pow(t_1, -1.0)), c_n) / Math.pow((1.0 - Math.pow((Math.exp(-t) + 1.0), -1.0)), c_n);
	} else {
		tmp = Math.pow((t_1 * 0.5), -c_p);
	}
	return tmp;
}
def code(c_p, c_n, t, s):
	t_1 = math.exp(-s) + 1.0
	tmp = 0
	if -s <= -1e-286:
		tmp = math.pow((1.0 - math.pow(t_1, -1.0)), c_n) / math.pow((1.0 - math.pow((math.exp(-t) + 1.0), -1.0)), c_n)
	else:
		tmp = math.pow((t_1 * 0.5), -c_p)
	return tmp
function code(c_p, c_n, t, s)
	t_1 = Float64(exp(Float64(-s)) + 1.0)
	tmp = 0.0
	if (Float64(-s) <= -1e-286)
		tmp = Float64((Float64(1.0 - (t_1 ^ -1.0)) ^ c_n) / (Float64(1.0 - (Float64(exp(Float64(-t)) + 1.0) ^ -1.0)) ^ c_n));
	else
		tmp = Float64(t_1 * 0.5) ^ Float64(-c_p);
	end
	return tmp
end
function tmp_2 = code(c_p, c_n, t, s)
	t_1 = exp(-s) + 1.0;
	tmp = 0.0;
	if (-s <= -1e-286)
		tmp = ((1.0 - (t_1 ^ -1.0)) ^ c_n) / ((1.0 - ((exp(-t) + 1.0) ^ -1.0)) ^ c_n);
	else
		tmp = (t_1 * 0.5) ^ -c_p;
	end
	tmp_2 = tmp;
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision]}, If[LessEqual[(-s), -1e-286], N[(N[Power[N[(1.0 - N[Power[t$95$1, -1.0], $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision] / N[Power[N[(1.0 - N[Power[N[(N[Exp[(-t)], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision], N[Power[N[(t$95$1 * 0.5), $MachinePrecision], (-c$95$p)], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := e^{-s} + 1\\
\mathbf{if}\;-s \leq -1 \cdot 10^{-286}:\\
\;\;\;\;\frac{{\left(1 - {t\_1}^{-1}\right)}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\

\mathbf{else}:\\
\;\;\;\;{\left(t\_1 \cdot 0.5\right)}^{\left(-c\_p\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (neg.f64 s) < -1.00000000000000005e-286

    1. Initial program 95.0%

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

      \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      3. lower--.f64N/A

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

        \[\leadsto \frac{{\left(1 - \color{blue}{\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      5. +-commutativeN/A

        \[\leadsto \frac{{\left(1 - \frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      6. lower-+.f64N/A

        \[\leadsto \frac{{\left(1 - \frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      7. lower-exp.f64N/A

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

        \[\leadsto \frac{{\left(1 - \frac{1}{e^{\color{blue}{-s}} + 1}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      9. lower-pow.f64N/A

        \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{{\left(1 - \frac{1}{e^{-t} + 1}\right)}^{c\_n}}} \]

    if -1.00000000000000005e-286 < (neg.f64 s)

    1. Initial program 92.8%

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

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
      4. +-commutativeN/A

        \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
      5. lower-+.f64N/A

        \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
      6. lower-exp.f64N/A

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

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

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}}^{c\_p}} \]
      10. +-commutativeN/A

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

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

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
      13. lower-neg.f6496.4

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
    5. Applied rewrites96.4%

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

      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_p}} \]
    7. Step-by-step derivation
      1. Applied rewrites97.1%

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p}} \]
      2. Step-by-step derivation
        1. Applied rewrites97.1%

          \[\leadsto \frac{{\left(e^{-s} + 1\right)}^{\left(-1 \cdot c\_p\right)}}{{\color{blue}{0.5}}^{c\_p}} \]
        2. Step-by-step derivation
          1. Applied rewrites97.8%

            \[\leadsto {\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\color{blue}{\left(-c\_p\right)}} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification98.8%

          \[\leadsto \begin{array}{l} \mathbf{if}\;-s \leq -1 \cdot 10^{-286}:\\ \;\;\;\;\frac{{\left(1 - {\left(e^{-s} + 1\right)}^{-1}\right)}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)}\\ \end{array} \]
        5. Add Preprocessing

        Alternative 2: 96.7% accurate, 2.1× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq -1 \cdot 10^{-38}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)}\\ \end{array} \end{array} \]
        (FPCore (c_p c_n t s)
         :precision binary64
         (if (<= t -1e-38)
           (/ (pow 0.5 c_n) (pow (- 1.0 (pow (+ (exp (- t)) 1.0) -1.0)) c_n))
           (pow (* (+ (exp (- s)) 1.0) 0.5) (- c_p))))
        double code(double c_p, double c_n, double t, double s) {
        	double tmp;
        	if (t <= -1e-38) {
        		tmp = pow(0.5, c_n) / pow((1.0 - pow((exp(-t) + 1.0), -1.0)), c_n);
        	} else {
        		tmp = pow(((exp(-s) + 1.0) * 0.5), -c_p);
        	}
        	return tmp;
        }
        
        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) :: tmp
            if (t <= (-1d-38)) then
                tmp = (0.5d0 ** c_n) / ((1.0d0 - ((exp(-t) + 1.0d0) ** (-1.0d0))) ** c_n)
            else
                tmp = ((exp(-s) + 1.0d0) * 0.5d0) ** -c_p
            end if
            code = tmp
        end function
        
        public static double code(double c_p, double c_n, double t, double s) {
        	double tmp;
        	if (t <= -1e-38) {
        		tmp = Math.pow(0.5, c_n) / Math.pow((1.0 - Math.pow((Math.exp(-t) + 1.0), -1.0)), c_n);
        	} else {
        		tmp = Math.pow(((Math.exp(-s) + 1.0) * 0.5), -c_p);
        	}
        	return tmp;
        }
        
        def code(c_p, c_n, t, s):
        	tmp = 0
        	if t <= -1e-38:
        		tmp = math.pow(0.5, c_n) / math.pow((1.0 - math.pow((math.exp(-t) + 1.0), -1.0)), c_n)
        	else:
        		tmp = math.pow(((math.exp(-s) + 1.0) * 0.5), -c_p)
        	return tmp
        
        function code(c_p, c_n, t, s)
        	tmp = 0.0
        	if (t <= -1e-38)
        		tmp = Float64((0.5 ^ c_n) / (Float64(1.0 - (Float64(exp(Float64(-t)) + 1.0) ^ -1.0)) ^ c_n));
        	else
        		tmp = Float64(Float64(exp(Float64(-s)) + 1.0) * 0.5) ^ Float64(-c_p);
        	end
        	return tmp
        end
        
        function tmp_2 = code(c_p, c_n, t, s)
        	tmp = 0.0;
        	if (t <= -1e-38)
        		tmp = (0.5 ^ c_n) / ((1.0 - ((exp(-t) + 1.0) ^ -1.0)) ^ c_n);
        	else
        		tmp = ((exp(-s) + 1.0) * 0.5) ^ -c_p;
        	end
        	tmp_2 = tmp;
        end
        
        code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[t, -1e-38], N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(1.0 - N[Power[N[(N[Exp[(-t)], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision] * 0.5), $MachinePrecision], (-c$95$p)], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;t \leq -1 \cdot 10^{-38}:\\
        \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\
        
        \mathbf{else}:\\
        \;\;\;\;{\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if t < -9.9999999999999996e-39

          1. Initial program 65.9%

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

            \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
          4. Step-by-step derivation
            1. lower-/.f64N/A

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

              \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
            3. lower--.f64N/A

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

              \[\leadsto \frac{{\left(1 - \color{blue}{\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
            5. +-commutativeN/A

              \[\leadsto \frac{{\left(1 - \frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
            6. lower-+.f64N/A

              \[\leadsto \frac{{\left(1 - \frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
            7. lower-exp.f64N/A

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

              \[\leadsto \frac{{\left(1 - \frac{1}{e^{\color{blue}{-s}} + 1}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
            9. lower-pow.f64N/A

              \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
          5. Applied rewrites96.2%

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

            \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
          7. Step-by-step derivation
            1. Applied rewrites96.2%

              \[\leadsto \frac{{0.5}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]

            if -9.9999999999999996e-39 < t

            1. Initial program 97.0%

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

              \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
            4. Step-by-step derivation
              1. lower-/.f64N/A

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

                \[\leadsto \frac{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
              3. lower-/.f64N/A

                \[\leadsto \frac{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
              4. +-commutativeN/A

                \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
              5. lower-+.f64N/A

                \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
              6. lower-exp.f64N/A

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

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

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
              9. lower-/.f64N/A

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}}^{c\_p}} \]
              10. +-commutativeN/A

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

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

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
              13. lower-neg.f6497.5

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
            5. Applied rewrites97.5%

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

              \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_p}} \]
            7. Step-by-step derivation
              1. Applied rewrites97.5%

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p}} \]
              2. Step-by-step derivation
                1. Applied rewrites97.5%

                  \[\leadsto \frac{{\left(e^{-s} + 1\right)}^{\left(-1 \cdot c\_p\right)}}{{\color{blue}{0.5}}^{c\_p}} \]
                2. Step-by-step derivation
                  1. Applied rewrites97.9%

                    \[\leadsto {\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\color{blue}{\left(-c\_p\right)}} \]
                3. Recombined 2 regimes into one program.
                4. Final simplification97.7%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -1 \cdot 10^{-38}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(1 - {\left(e^{-t} + 1\right)}^{-1}\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)}\\ \end{array} \]
                5. Add Preprocessing

                Alternative 3: 95.6% accurate, 4.2× speedup?

                \[\begin{array}{l} \\ {\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)} \end{array} \]
                (FPCore (c_p c_n t s)
                 :precision binary64
                 (pow (* (+ (exp (- s)) 1.0) 0.5) (- c_p)))
                double code(double c_p, double c_n, double t, double s) {
                	return pow(((exp(-s) + 1.0) * 0.5), -c_p);
                }
                
                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 = ((exp(-s) + 1.0d0) * 0.5d0) ** -c_p
                end function
                
                public static double code(double c_p, double c_n, double t, double s) {
                	return Math.pow(((Math.exp(-s) + 1.0) * 0.5), -c_p);
                }
                
                def code(c_p, c_n, t, s):
                	return math.pow(((math.exp(-s) + 1.0) * 0.5), -c_p)
                
                function code(c_p, c_n, t, s)
                	return Float64(Float64(exp(Float64(-s)) + 1.0) * 0.5) ^ Float64(-c_p)
                end
                
                function tmp = code(c_p, c_n, t, s)
                	tmp = ((exp(-s) + 1.0) * 0.5) ^ -c_p;
                end
                
                code[c$95$p_, c$95$n_, t_, s_] := N[Power[N[(N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision] * 0.5), $MachinePrecision], (-c$95$p)], $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                {\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\left(-c\_p\right)}
                \end{array}
                
                Derivation
                1. Initial program 93.8%

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

                  \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
                4. Step-by-step derivation
                  1. lower-/.f64N/A

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

                    \[\leadsto \frac{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                  3. lower-/.f64N/A

                    \[\leadsto \frac{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                  4. +-commutativeN/A

                    \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                  5. lower-+.f64N/A

                    \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                  6. lower-exp.f64N/A

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

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

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
                  9. lower-/.f64N/A

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}}^{c\_p}} \]
                  10. +-commutativeN/A

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

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

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                  13. lower-neg.f6494.6

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                5. Applied rewrites94.6%

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

                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_p}} \]
                7. Step-by-step derivation
                  1. Applied rewrites95.6%

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p}} \]
                  2. Step-by-step derivation
                    1. Applied rewrites95.6%

                      \[\leadsto \frac{{\left(e^{-s} + 1\right)}^{\left(-1 \cdot c\_p\right)}}{{\color{blue}{0.5}}^{c\_p}} \]
                    2. Step-by-step derivation
                      1. Applied rewrites96.0%

                        \[\leadsto {\left(\left(e^{-s} + 1\right) \cdot 0.5\right)}^{\color{blue}{\left(-c\_p\right)}} \]
                      2. Add Preprocessing

                      Alternative 4: 94.0% 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 93.8%

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

                        \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
                      4. Step-by-step derivation
                        1. lower-/.f64N/A

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

                          \[\leadsto \frac{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                        3. lower-/.f64N/A

                          \[\leadsto \frac{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                        4. +-commutativeN/A

                          \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                        5. lower-+.f64N/A

                          \[\leadsto \frac{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(s\right)} + 1}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}} \]
                        6. lower-exp.f64N/A

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

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

                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\color{blue}{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_p}}} \]
                        9. lower-/.f64N/A

                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\color{blue}{\left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}}^{c\_p}} \]
                        10. +-commutativeN/A

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

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

                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                        13. lower-neg.f6494.6

                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                      5. Applied rewrites94.6%

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

                        \[\leadsto 1 \]
                      7. Step-by-step derivation
                        1. Applied rewrites95.6%

                          \[\leadsto 1 \]
                        2. Add Preprocessing

                        Developer Target 1: 96.4% 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 2024318 
                        (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))))