Harley's example

Percentage Accurate: 90.5% → 99.0%
Time: 2.3min
Alternatives: 7
Speedup: 835.0×

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 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: 90.5% 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: 99.0% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;c\_p \leq 5 \cdot 10^{-30}:\\ \;\;\;\;{\left(\sqrt{e^{\left(\left(c\_n \cdot \mathsf{log1p}\left(\frac{1}{e^{s} + 1}\right) - c\_p \cdot \mathsf{log1p}\left(e^{s}\right)\right) - c\_n \cdot \mathsf{log1p}\left(\frac{1}{1 + e^{t}}\right)\right) + c\_p \cdot \mathsf{log1p}\left(e^{t}\right)}}\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (if (<= c_p 5e-30)
   (pow
    (sqrt
     (exp
      (+
       (-
        (- (* c_n (log1p (/ 1.0 (+ (exp s) 1.0)))) (* c_p (log1p (exp s))))
        (* c_n (log1p (/ 1.0 (+ 1.0 (exp t))))))
       (* c_p (log1p (exp t))))))
    2.0)
   (exp (* c_p (- (log1p (exp (- t))) (log1p (exp (- s))))))))
double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 5e-30) {
		tmp = pow(sqrt(exp(((((c_n * log1p((1.0 / (exp(s) + 1.0)))) - (c_p * log1p(exp(s)))) - (c_n * log1p((1.0 / (1.0 + exp(t)))))) + (c_p * log1p(exp(t)))))), 2.0);
	} else {
		tmp = exp((c_p * (log1p(exp(-t)) - log1p(exp(-s)))));
	}
	return tmp;
}
public static double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 5e-30) {
		tmp = Math.pow(Math.sqrt(Math.exp(((((c_n * Math.log1p((1.0 / (Math.exp(s) + 1.0)))) - (c_p * Math.log1p(Math.exp(s)))) - (c_n * Math.log1p((1.0 / (1.0 + Math.exp(t)))))) + (c_p * Math.log1p(Math.exp(t)))))), 2.0);
	} else {
		tmp = Math.exp((c_p * (Math.log1p(Math.exp(-t)) - Math.log1p(Math.exp(-s)))));
	}
	return tmp;
}
def code(c_p, c_n, t, s):
	tmp = 0
	if c_p <= 5e-30:
		tmp = math.pow(math.sqrt(math.exp(((((c_n * math.log1p((1.0 / (math.exp(s) + 1.0)))) - (c_p * math.log1p(math.exp(s)))) - (c_n * math.log1p((1.0 / (1.0 + math.exp(t)))))) + (c_p * math.log1p(math.exp(t)))))), 2.0)
	else:
		tmp = math.exp((c_p * (math.log1p(math.exp(-t)) - math.log1p(math.exp(-s)))))
	return tmp
function code(c_p, c_n, t, s)
	tmp = 0.0
	if (c_p <= 5e-30)
		tmp = sqrt(exp(Float64(Float64(Float64(Float64(c_n * log1p(Float64(1.0 / Float64(exp(s) + 1.0)))) - Float64(c_p * log1p(exp(s)))) - Float64(c_n * log1p(Float64(1.0 / Float64(1.0 + exp(t)))))) + Float64(c_p * log1p(exp(t)))))) ^ 2.0;
	else
		tmp = exp(Float64(c_p * Float64(log1p(exp(Float64(-t))) - log1p(exp(Float64(-s))))));
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[c$95$p, 5e-30], N[Power[N[Sqrt[N[Exp[N[(N[(N[(N[(c$95$n * N[Log[1 + N[(1.0 / N[(N[Exp[s], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - N[(c$95$p * N[Log[1 + N[Exp[s], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c$95$n * N[Log[1 + N[(1.0 / N[(1.0 + N[Exp[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(c$95$p * N[Log[1 + N[Exp[t], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision], N[Exp[N[(c$95$p * N[(N[Log[1 + N[Exp[(-t)], $MachinePrecision]], $MachinePrecision] - N[Log[1 + N[Exp[(-s)], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;c\_p \leq 5 \cdot 10^{-30}:\\
\;\;\;\;{\left(\sqrt{e^{\left(\left(c\_n \cdot \mathsf{log1p}\left(\frac{1}{e^{s} + 1}\right) - c\_p \cdot \mathsf{log1p}\left(e^{s}\right)\right) - c\_n \cdot \mathsf{log1p}\left(\frac{1}{1 + e^{t}}\right)\right) + c\_p \cdot \mathsf{log1p}\left(e^{t}\right)}}\right)}^{2}\\

\mathbf{else}:\\
\;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if c_p < 4.99999999999999972e-30

    1. Initial program 90.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/90.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified90.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Applied egg-rr99.2%

      \[\leadsto \color{blue}{{\left(\sqrt{e^{\left(\left(c\_p \cdot \left(-\mathsf{log1p}\left(e^{s}\right)\right) + c\_n \cdot \mathsf{log1p}\left(\frac{1}{1 + e^{s}}\right)\right) - c\_n \cdot \mathsf{log1p}\left(\frac{1}{1 + e^{t}}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{t}\right)\right)}}\right)}^{2}} \]

    if 4.99999999999999972e-30 < c_p

    1. Initial program 57.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/57.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified57.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Taylor expanded in c_n around 0 65.7%

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    6. Step-by-step derivation
      1. add-exp-log65.7%

        \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
      2. log-div65.7%

        \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
      3. log-pow69.0%

        \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      4. log-rec69.0%

        \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      5. log1p-define69.0%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      6. log-pow99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
      7. neg-log99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
      8. log1p-define99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
    7. Applied egg-rr99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
    8. Step-by-step derivation
      1. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      2. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      3. distribute-lft-out--99.4%

        \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
      4. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
      5. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    9. Simplified99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;c\_p \leq 5 \cdot 10^{-30}:\\ \;\;\;\;{\left(\sqrt{e^{\left(\left(c\_n \cdot \mathsf{log1p}\left(\frac{1}{e^{s} + 1}\right) - c\_p \cdot \mathsf{log1p}\left(e^{s}\right)\right) - c\_n \cdot \mathsf{log1p}\left(\frac{1}{1 + e^{t}}\right)\right) + c\_p \cdot \mathsf{log1p}\left(e^{t}\right)}}\right)}^{2}\\ \mathbf{else}:\\ \;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.2% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;c\_p \leq 3 \cdot 10^{-29}:\\ \;\;\;\;{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}\\ \mathbf{else}:\\ \;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (if (<= c_p 3e-29)
   (pow (/ 2.0 (+ (exp s) 1.0)) c_p)
   (exp (* c_p (- (log1p (exp (- t))) (log1p (exp (- s))))))))
double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 3e-29) {
		tmp = pow((2.0 / (exp(s) + 1.0)), c_p);
	} else {
		tmp = exp((c_p * (log1p(exp(-t)) - log1p(exp(-s)))));
	}
	return tmp;
}
public static double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 3e-29) {
		tmp = Math.pow((2.0 / (Math.exp(s) + 1.0)), c_p);
	} else {
		tmp = Math.exp((c_p * (Math.log1p(Math.exp(-t)) - Math.log1p(Math.exp(-s)))));
	}
	return tmp;
}
def code(c_p, c_n, t, s):
	tmp = 0
	if c_p <= 3e-29:
		tmp = math.pow((2.0 / (math.exp(s) + 1.0)), c_p)
	else:
		tmp = math.exp((c_p * (math.log1p(math.exp(-t)) - math.log1p(math.exp(-s)))))
	return tmp
function code(c_p, c_n, t, s)
	tmp = 0.0
	if (c_p <= 3e-29)
		tmp = Float64(2.0 / Float64(exp(s) + 1.0)) ^ c_p;
	else
		tmp = exp(Float64(c_p * Float64(log1p(exp(Float64(-t))) - log1p(exp(Float64(-s))))));
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[c$95$p, 3e-29], N[Power[N[(2.0 / N[(N[Exp[s], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision], N[Exp[N[(c$95$p * N[(N[Log[1 + N[Exp[(-t)], $MachinePrecision]], $MachinePrecision] - N[Log[1 + N[Exp[(-s)], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;c\_p \leq 3 \cdot 10^{-29}:\\
\;\;\;\;{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}\\

\mathbf{else}:\\
\;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if c_p < 3.0000000000000003e-29

    1. Initial program 90.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/90.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified90.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Taylor expanded in c_n around 0 93.8%

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    6. Step-by-step derivation
      1. add-exp-log93.8%

        \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
      2. log-div93.8%

        \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
      3. log-pow93.8%

        \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      4. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      5. log1p-define93.8%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      6. log-pow93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
      7. neg-log93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
      8. log1p-define93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
    7. Applied egg-rr93.8%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
    8. Step-by-step derivation
      1. log1p-undefine93.8%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      2. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      3. distribute-lft-out--93.8%

        \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
      4. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
      5. log1p-undefine93.8%

        \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    9. Simplified93.8%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
    10. Taylor expanded in t around 0 94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \log \left(1 + e^{-s}\right)\right)}} \]
    11. Step-by-step derivation
      1. log1p-define94.7%

        \[\leadsto e^{c\_p \cdot \left(\log 2 - \color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right)} \]
    12. Simplified94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}} \]
    13. Step-by-step derivation
      1. *-commutative94.7%

        \[\leadsto e^{\color{blue}{\left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right) \cdot c\_p}} \]
      2. exp-prod94.7%

        \[\leadsto \color{blue}{{\left(e^{\log 2 - \mathsf{log1p}\left(e^{-s}\right)}\right)}^{c\_p}} \]
      3. exp-diff94.7%

        \[\leadsto {\color{blue}{\left(\frac{e^{\log 2}}{e^{\mathsf{log1p}\left(e^{-s}\right)}}\right)}}^{c\_p} \]
      4. log1p-undefine94.7%

        \[\leadsto {\left(\frac{e^{\log 2}}{e^{\color{blue}{\log \left(1 + e^{-s}\right)}}}\right)}^{c\_p} \]
      5. add-exp-log94.7%

        \[\leadsto {\left(\frac{e^{\log 2}}{\color{blue}{1 + e^{-s}}}\right)}^{c\_p} \]
      6. rem-exp-log94.7%

        \[\leadsto {\left(\frac{\color{blue}{2}}{1 + e^{-s}}\right)}^{c\_p} \]
      7. +-commutative94.7%

        \[\leadsto {\left(\frac{2}{\color{blue}{e^{-s} + 1}}\right)}^{c\_p} \]
      8. add-sqr-sqrt47.9%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{-s} \cdot \sqrt{-s}}} + 1}\right)}^{c\_p} \]
      9. sqrt-unprod97.4%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{\left(-s\right) \cdot \left(-s\right)}}} + 1}\right)}^{c\_p} \]
      10. sqr-neg97.4%

        \[\leadsto {\left(\frac{2}{e^{\sqrt{\color{blue}{s \cdot s}}} + 1}\right)}^{c\_p} \]
      11. sqrt-unprod49.5%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{s} \cdot \sqrt{s}}} + 1}\right)}^{c\_p} \]
      12. add-sqr-sqrt98.3%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{s}} + 1}\right)}^{c\_p} \]
    14. Applied egg-rr98.3%

      \[\leadsto \color{blue}{{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}} \]

    if 3.0000000000000003e-29 < c_p

    1. Initial program 57.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/57.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified57.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Taylor expanded in c_n around 0 65.7%

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    6. Step-by-step derivation
      1. add-exp-log65.7%

        \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
      2. log-div65.7%

        \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
      3. log-pow69.0%

        \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      4. log-rec69.0%

        \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      5. log1p-define69.0%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      6. log-pow99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
      7. neg-log99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
      8. log1p-define99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
    7. Applied egg-rr99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
    8. Step-by-step derivation
      1. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      2. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      3. distribute-lft-out--99.4%

        \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
      4. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
      5. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    9. Simplified99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;c\_p \leq 3 \cdot 10^{-29}:\\ \;\;\;\;{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}\\ \mathbf{else}:\\ \;\;\;\;e^{c\_p \cdot \left(\mathsf{log1p}\left(e^{-t}\right) - \mathsf{log1p}\left(e^{-s}\right)\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 97.9% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;c\_p \leq 2 \cdot 10^{-29}:\\ \;\;\;\;{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}\\ \mathbf{else}:\\ \;\;\;\;e^{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (if (<= c_p 2e-29)
   (pow (/ 2.0 (+ (exp s) 1.0)) c_p)
   (exp (* c_p (- (log 2.0) (log1p (exp (- s))))))))
double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 2e-29) {
		tmp = pow((2.0 / (exp(s) + 1.0)), c_p);
	} else {
		tmp = exp((c_p * (log(2.0) - log1p(exp(-s)))));
	}
	return tmp;
}
public static double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (c_p <= 2e-29) {
		tmp = Math.pow((2.0 / (Math.exp(s) + 1.0)), c_p);
	} else {
		tmp = Math.exp((c_p * (Math.log(2.0) - Math.log1p(Math.exp(-s)))));
	}
	return tmp;
}
def code(c_p, c_n, t, s):
	tmp = 0
	if c_p <= 2e-29:
		tmp = math.pow((2.0 / (math.exp(s) + 1.0)), c_p)
	else:
		tmp = math.exp((c_p * (math.log(2.0) - math.log1p(math.exp(-s)))))
	return tmp
function code(c_p, c_n, t, s)
	tmp = 0.0
	if (c_p <= 2e-29)
		tmp = Float64(2.0 / Float64(exp(s) + 1.0)) ^ c_p;
	else
		tmp = exp(Float64(c_p * Float64(log(2.0) - log1p(exp(Float64(-s))))));
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[c$95$p, 2e-29], N[Power[N[(2.0 / N[(N[Exp[s], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision], N[Exp[N[(c$95$p * N[(N[Log[2.0], $MachinePrecision] - N[Log[1 + N[Exp[(-s)], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;c\_p \leq 2 \cdot 10^{-29}:\\
\;\;\;\;{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}\\

\mathbf{else}:\\
\;\;\;\;e^{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if c_p < 1.99999999999999989e-29

    1. Initial program 90.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/90.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified90.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Taylor expanded in c_n around 0 93.8%

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    6. Step-by-step derivation
      1. add-exp-log93.8%

        \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
      2. log-div93.8%

        \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
      3. log-pow93.8%

        \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      4. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      5. log1p-define93.8%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      6. log-pow93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
      7. neg-log93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
      8. log1p-define93.8%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
    7. Applied egg-rr93.8%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
    8. Step-by-step derivation
      1. log1p-undefine93.8%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      2. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      3. distribute-lft-out--93.8%

        \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
      4. log-rec93.8%

        \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
      5. log1p-undefine93.8%

        \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    9. Simplified93.8%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
    10. Taylor expanded in t around 0 94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \log \left(1 + e^{-s}\right)\right)}} \]
    11. Step-by-step derivation
      1. log1p-define94.7%

        \[\leadsto e^{c\_p \cdot \left(\log 2 - \color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right)} \]
    12. Simplified94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}} \]
    13. Step-by-step derivation
      1. *-commutative94.7%

        \[\leadsto e^{\color{blue}{\left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right) \cdot c\_p}} \]
      2. exp-prod94.7%

        \[\leadsto \color{blue}{{\left(e^{\log 2 - \mathsf{log1p}\left(e^{-s}\right)}\right)}^{c\_p}} \]
      3. exp-diff94.7%

        \[\leadsto {\color{blue}{\left(\frac{e^{\log 2}}{e^{\mathsf{log1p}\left(e^{-s}\right)}}\right)}}^{c\_p} \]
      4. log1p-undefine94.7%

        \[\leadsto {\left(\frac{e^{\log 2}}{e^{\color{blue}{\log \left(1 + e^{-s}\right)}}}\right)}^{c\_p} \]
      5. add-exp-log94.7%

        \[\leadsto {\left(\frac{e^{\log 2}}{\color{blue}{1 + e^{-s}}}\right)}^{c\_p} \]
      6. rem-exp-log94.7%

        \[\leadsto {\left(\frac{\color{blue}{2}}{1 + e^{-s}}\right)}^{c\_p} \]
      7. +-commutative94.7%

        \[\leadsto {\left(\frac{2}{\color{blue}{e^{-s} + 1}}\right)}^{c\_p} \]
      8. add-sqr-sqrt47.9%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{-s} \cdot \sqrt{-s}}} + 1}\right)}^{c\_p} \]
      9. sqrt-unprod97.4%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{\left(-s\right) \cdot \left(-s\right)}}} + 1}\right)}^{c\_p} \]
      10. sqr-neg97.4%

        \[\leadsto {\left(\frac{2}{e^{\sqrt{\color{blue}{s \cdot s}}} + 1}\right)}^{c\_p} \]
      11. sqrt-unprod49.5%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{\sqrt{s} \cdot \sqrt{s}}} + 1}\right)}^{c\_p} \]
      12. add-sqr-sqrt98.3%

        \[\leadsto {\left(\frac{2}{e^{\color{blue}{s}} + 1}\right)}^{c\_p} \]
    14. Applied egg-rr98.3%

      \[\leadsto \color{blue}{{\left(\frac{2}{e^{s} + 1}\right)}^{c\_p}} \]

    if 1.99999999999999989e-29 < c_p

    1. Initial program 57.9%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    2. Step-by-step derivation
      1. associate-/l/57.9%

        \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    3. Simplified57.9%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    4. Add Preprocessing
    5. Taylor expanded in c_n around 0 65.7%

      \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
    6. Step-by-step derivation
      1. add-exp-log65.7%

        \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
      2. log-div65.7%

        \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
      3. log-pow69.0%

        \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      4. log-rec69.0%

        \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      5. log1p-define69.0%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
      6. log-pow99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
      7. neg-log99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
      8. log1p-define99.4%

        \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
    7. Applied egg-rr99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
    8. Step-by-step derivation
      1. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      2. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
      3. distribute-lft-out--99.4%

        \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
      4. log-rec99.4%

        \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
      5. log1p-undefine99.4%

        \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    9. Simplified99.4%

      \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
    10. Taylor expanded in t around 0 96.8%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \log \left(1 + e^{-s}\right)\right)}} \]
    11. Step-by-step derivation
      1. log1p-define96.8%

        \[\leadsto e^{c\_p \cdot \left(\log 2 - \color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right)} \]
    12. Simplified96.8%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 97.8% accurate, 7.7× speedup?

\[\begin{array}{l} \\ e^{c\_p \cdot \left(s \cdot \left(0.5 + s \cdot -0.125\right)\right)} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (exp (* c_p (* s (+ 0.5 (* s -0.125))))))
double code(double c_p, double c_n, double t, double s) {
	return exp((c_p * (s * (0.5 + (s * -0.125)))));
}
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((c_p * (s * (0.5d0 + (s * (-0.125d0))))))
end function
public static double code(double c_p, double c_n, double t, double s) {
	return Math.exp((c_p * (s * (0.5 + (s * -0.125)))));
}
def code(c_p, c_n, t, s):
	return math.exp((c_p * (s * (0.5 + (s * -0.125)))))
function code(c_p, c_n, t, s)
	return exp(Float64(c_p * Float64(s * Float64(0.5 + Float64(s * -0.125)))))
end
function tmp = code(c_p, c_n, t, s)
	tmp = exp((c_p * (s * (0.5 + (s * -0.125)))));
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(c$95$p * N[(s * N[(0.5 + N[(s * -0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{c\_p \cdot \left(s \cdot \left(0.5 + s \cdot -0.125\right)\right)}
\end{array}
Derivation
  1. Initial program 86.0%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Step-by-step derivation
    1. associate-/l/86.0%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  3. Simplified86.0%

    \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  4. Add Preprocessing
  5. Taylor expanded in c_n around 0 89.7%

    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  6. Step-by-step derivation
    1. add-exp-log89.7%

      \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
    2. log-div89.7%

      \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
    3. log-pow90.2%

      \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    4. log-rec90.2%

      \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    5. log1p-define90.2%

      \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    6. log-pow94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
    7. neg-log94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
    8. log1p-define94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
  7. Applied egg-rr94.7%

    \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
  8. Step-by-step derivation
    1. log1p-undefine94.7%

      \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
    2. log-rec94.7%

      \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
    3. distribute-lft-out--94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
    4. log-rec94.7%

      \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    5. log1p-undefine94.7%

      \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
  9. Simplified94.7%

    \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
  10. Taylor expanded in t around 0 95.1%

    \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \log \left(1 + e^{-s}\right)\right)}} \]
  11. Step-by-step derivation
    1. log1p-define95.1%

      \[\leadsto e^{c\_p \cdot \left(\log 2 - \color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right)} \]
  12. Simplified95.1%

    \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}} \]
  13. Taylor expanded in s around 0 96.4%

    \[\leadsto e^{c\_p \cdot \color{blue}{\left(s \cdot \left(0.5 + -0.125 \cdot s\right)\right)}} \]
  14. Step-by-step derivation
    1. *-commutative96.4%

      \[\leadsto e^{c\_p \cdot \left(s \cdot \left(0.5 + \color{blue}{s \cdot -0.125}\right)\right)} \]
  15. Simplified96.4%

    \[\leadsto e^{c\_p \cdot \color{blue}{\left(s \cdot \left(0.5 + s \cdot -0.125\right)\right)}} \]
  16. Add Preprocessing

Alternative 5: 96.4% accurate, 8.0× speedup?

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

\\
e^{c\_p \cdot \left(s \cdot 0.5\right)}
\end{array}
Derivation
  1. Initial program 86.0%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Step-by-step derivation
    1. associate-/l/86.0%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  3. Simplified86.0%

    \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  4. Add Preprocessing
  5. Taylor expanded in c_n around 0 89.7%

    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  6. Step-by-step derivation
    1. add-exp-log89.7%

      \[\leadsto \color{blue}{e^{\log \left(\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}\right)}} \]
    2. log-div89.7%

      \[\leadsto e^{\color{blue}{\log \left({\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)}} \]
    3. log-pow90.2%

      \[\leadsto e^{\color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-s}}\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    4. log-rec90.2%

      \[\leadsto e^{c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    5. log1p-define90.2%

      \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left({\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}\right)} \]
    6. log-pow94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{-t}}\right)}} \]
    7. neg-log94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \color{blue}{\left(-\log \left(1 + e^{-t}\right)\right)}} \]
    8. log1p-define94.7%

      \[\leadsto e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\color{blue}{\mathsf{log1p}\left(e^{-t}\right)}\right)} \]
  7. Applied egg-rr94.7%

    \[\leadsto \color{blue}{e^{c\_p \cdot \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)}} \]
  8. Step-by-step derivation
    1. log1p-undefine94.7%

      \[\leadsto e^{c\_p \cdot \left(-\color{blue}{\log \left(1 + e^{-s}\right)}\right) - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
    2. log-rec94.7%

      \[\leadsto e^{c\_p \cdot \color{blue}{\log \left(\frac{1}{1 + e^{-s}}\right)} - c\_p \cdot \left(-\mathsf{log1p}\left(e^{-t}\right)\right)} \]
    3. distribute-lft-out--94.7%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log \left(\frac{1}{1 + e^{-s}}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
    4. log-rec94.7%

      \[\leadsto e^{c\_p \cdot \left(\color{blue}{\left(-\log \left(1 + e^{-s}\right)\right)} - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
    5. log1p-undefine94.7%

      \[\leadsto e^{c\_p \cdot \left(\left(-\color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)} \]
  9. Simplified94.7%

    \[\leadsto \color{blue}{e^{c\_p \cdot \left(\left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right)\right)}} \]
  10. Taylor expanded in t around 0 95.1%

    \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \log \left(1 + e^{-s}\right)\right)}} \]
  11. Step-by-step derivation
    1. log1p-define95.1%

      \[\leadsto e^{c\_p \cdot \left(\log 2 - \color{blue}{\mathsf{log1p}\left(e^{-s}\right)}\right)} \]
  12. Simplified95.1%

    \[\leadsto e^{\color{blue}{c\_p \cdot \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right)}} \]
  13. Taylor expanded in s around 0 95.6%

    \[\leadsto e^{\color{blue}{0.5 \cdot \left(c\_p \cdot s\right)}} \]
  14. Step-by-step derivation
    1. *-commutative95.6%

      \[\leadsto e^{\color{blue}{\left(c\_p \cdot s\right) \cdot 0.5}} \]
    2. associate-*l*95.6%

      \[\leadsto e^{\color{blue}{c\_p \cdot \left(s \cdot 0.5\right)}} \]
  15. Simplified95.6%

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

Alternative 6: 94.0% accurate, 119.3× speedup?

\[\begin{array}{l} \\ 1 + -0.5 \cdot \left(c\_p \cdot t\right) \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 (+ 1.0 (* -0.5 (* c_p t))))
double code(double c_p, double c_n, double t, double s) {
	return 1.0 + (-0.5 * (c_p * t));
}
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 + ((-0.5d0) * (c_p * t))
end function
public static double code(double c_p, double c_n, double t, double s) {
	return 1.0 + (-0.5 * (c_p * t));
}
def code(c_p, c_n, t, s):
	return 1.0 + (-0.5 * (c_p * t))
function code(c_p, c_n, t, s)
	return Float64(1.0 + Float64(-0.5 * Float64(c_p * t)))
end
function tmp = code(c_p, c_n, t, s)
	tmp = 1.0 + (-0.5 * (c_p * t));
end
code[c$95$p_, c$95$n_, t_, s_] := N[(1.0 + N[(-0.5 * N[(c$95$p * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + -0.5 \cdot \left(c\_p \cdot t\right)
\end{array}
Derivation
  1. Initial program 86.0%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Step-by-step derivation
    1. associate-/l/86.0%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  3. Simplified86.0%

    \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  4. Add Preprocessing
  5. Taylor expanded in c_n around 0 89.7%

    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  6. Taylor expanded in s around 0 89.5%

    \[\leadsto \color{blue}{\frac{{0.5}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  7. Taylor expanded in t around 0 93.1%

    \[\leadsto \color{blue}{1 + -0.5 \cdot \left(c\_p \cdot t\right)} \]
  8. Add Preprocessing

Alternative 7: 94.0% accurate, 835.0× 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 86.0%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Step-by-step derivation
    1. associate-/l/86.0%

      \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  3. Simplified86.0%

    \[\leadsto \color{blue}{\frac{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  4. Add Preprocessing
  5. Taylor expanded in c_n around 0 89.7%

    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p}}} \]
  6. Taylor expanded in c_p around 0 93.0%

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

Developer Target 1: 96.2% accurate, 1.3× 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 2024165 
(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))))