Harley's example

Percentage Accurate: 90.9% → 95.5%
Time: 49.5s
Alternatives: 5
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 5 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 90.9% accurate, 1.0× speedup?

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

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

Alternative 1: 95.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\\ t_2 := e^{-t}\\ t_3 := e^{-s}\\ t_4 := \frac{{\left(\frac{1}{1 + t\_3}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - t\_3}\right)}^{c\_n}}{{\left(\frac{1}{1 + t\_2}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - t\_2}\right)}^{c\_n}}\\ \mathbf{if}\;t\_4 \leq 2:\\ \;\;\;\;t\_4\\ \mathbf{else}:\\ \;\;\;\;{\left(t\_1 \cdot t\_1\right)}^{\left(-c\_p \cdot 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (fma s (fma s (fma s -0.16666666666666666 0.5) -1.0) 2.0))
        (t_2 (exp (- t)))
        (t_3 (exp (- s)))
        (t_4
         (/
          (*
           (pow (/ 1.0 (+ 1.0 t_3)) c_p)
           (pow (+ 1.0 (/ 1.0 (- -1.0 t_3))) c_n))
          (*
           (pow (/ 1.0 (+ 1.0 t_2)) c_p)
           (pow (+ 1.0 (/ 1.0 (- -1.0 t_2))) c_n)))))
   (if (<= t_4 2.0) t_4 (pow (* t_1 t_1) (- (* c_p 0.5))))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = fma(s, fma(s, fma(s, -0.16666666666666666, 0.5), -1.0), 2.0);
	double t_2 = exp(-t);
	double t_3 = exp(-s);
	double t_4 = (pow((1.0 / (1.0 + t_3)), c_p) * pow((1.0 + (1.0 / (-1.0 - t_3))), c_n)) / (pow((1.0 / (1.0 + t_2)), c_p) * pow((1.0 + (1.0 / (-1.0 - t_2))), c_n));
	double tmp;
	if (t_4 <= 2.0) {
		tmp = t_4;
	} else {
		tmp = pow((t_1 * t_1), -(c_p * 0.5));
	}
	return tmp;
}
function code(c_p, c_n, t, s)
	t_1 = fma(s, fma(s, fma(s, -0.16666666666666666, 0.5), -1.0), 2.0)
	t_2 = exp(Float64(-t))
	t_3 = exp(Float64(-s))
	t_4 = Float64(Float64((Float64(1.0 / Float64(1.0 + t_3)) ^ c_p) * (Float64(1.0 + Float64(1.0 / Float64(-1.0 - t_3))) ^ c_n)) / Float64((Float64(1.0 / Float64(1.0 + t_2)) ^ c_p) * (Float64(1.0 + Float64(1.0 / Float64(-1.0 - t_2))) ^ c_n)))
	tmp = 0.0
	if (t_4 <= 2.0)
		tmp = t_4;
	else
		tmp = Float64(t_1 * t_1) ^ Float64(-Float64(c_p * 0.5));
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(s * N[(s * N[(s * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t)], $MachinePrecision]}, Block[{t$95$3 = N[Exp[(-s)], $MachinePrecision]}, Block[{t$95$4 = N[(N[(N[Power[N[(1.0 / N[(1.0 + t$95$3), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(1.0 + N[(1.0 / N[(-1.0 - t$95$3), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[N[(1.0 / N[(1.0 + t$95$2), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(1.0 + N[(1.0 / N[(-1.0 - t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$4, 2.0], t$95$4, N[Power[N[(t$95$1 * t$95$1), $MachinePrecision], (-N[(c$95$p * 0.5), $MachinePrecision])], $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\\
t_2 := e^{-t}\\
t_3 := e^{-s}\\
t_4 := \frac{{\left(\frac{1}{1 + t\_3}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - t\_3}\right)}^{c\_n}}{{\left(\frac{1}{1 + t\_2}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - t\_2}\right)}^{c\_n}}\\
\mathbf{if}\;t\_4 \leq 2:\\
\;\;\;\;t\_4\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 (pow.f64 (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 s)))) c_p) (pow.f64 (-.f64 #s(literal 1 binary64) (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 s))))) c_n)) (*.f64 (pow.f64 (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 t)))) c_p) (pow.f64 (-.f64 #s(literal 1 binary64) (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 t))))) c_n))) < 2

    1. Initial program 99.6%

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

    if 2 < (/.f64 (*.f64 (pow.f64 (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 s)))) c_p) (pow.f64 (-.f64 #s(literal 1 binary64) (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 s))))) c_n)) (*.f64 (pow.f64 (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 t)))) c_p) (pow.f64 (-.f64 #s(literal 1 binary64) (/.f64 #s(literal 1 binary64) (+.f64 #s(literal 1 binary64) (exp.f64 (neg.f64 t))))) c_n)))

    1. Initial program 0.5%

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

      \[\leadsto \frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    4. Step-by-step derivation
      1. Simplified50.2%

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

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

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

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

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

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

          \[\leadsto {\left(\frac{1}{1 + \color{blue}{e^{-1 \cdot s}}}\right)}^{c\_p} \]
        6. neg-mul-1N/A

          \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{c\_p} \]
        7. lower-neg.f6465.3

          \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{-s}}}\right)}^{c\_p} \]
      4. Simplified65.3%

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

        \[\leadsto {\left(\frac{1}{\color{blue}{2 + s \cdot \left(s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1\right)}}\right)}^{c\_p} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto {\left(\frac{1}{\color{blue}{s \cdot \left(s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1\right) + 2}}\right)}^{c\_p} \]
        2. lower-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1, 2\right)}}\right)}^{c\_p} \]
        3. sub-negN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) + \left(\mathsf{neg}\left(1\right)\right)}, 2\right)}\right)}^{c\_p} \]
        4. metadata-evalN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) + \color{blue}{-1}, 2\right)}\right)}^{c\_p} \]
        5. lower-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(s, \frac{1}{2} + \frac{-1}{6} \cdot s, -1\right)}, 2\right)}\right)}^{c\_p} \]
        6. +-commutativeN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{\frac{-1}{6} \cdot s + \frac{1}{2}}, -1\right), 2\right)}\right)}^{c\_p} \]
        7. *-commutativeN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{s \cdot \frac{-1}{6}} + \frac{1}{2}, -1\right), 2\right)}\right)}^{c\_p} \]
        8. lower-fma.f6475.9

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(s, -0.16666666666666666, 0.5\right)}, -1\right), 2\right)}\right)}^{c\_p} \]
      7. Simplified75.9%

        \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)}}\right)}^{c\_p} \]
      8. Step-by-step derivation
        1. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{s \cdot \left(s \cdot \color{blue}{\mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right)} + -1\right) + 2}\right)}^{c\_p} \]
        2. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{s \cdot \color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right)} + 2}\right)}^{c\_p} \]
        3. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}}\right)}^{c\_p} \]
        4. lift-/.f64N/A

          \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{c\_p} \]
        5. sqr-powN/A

          \[\leadsto \color{blue}{{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)}} \]
        6. lift-/.f64N/A

          \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        7. inv-powN/A

          \[\leadsto {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        8. pow-powN/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        9. lift-/.f64N/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
        10. inv-powN/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
        11. pow-powN/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
        12. pow-prod-downN/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
        13. lower-pow.f64N/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
      9. Applied egg-rr81.5%

        \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\right)}^{\left(-c\_p \cdot 0.5\right)}} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification98.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}} \leq 2:\\ \;\;\;\;\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 + \frac{1}{-1 - e^{-t}}\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\right)}^{\left(-c\_p \cdot 0.5\right)}\\ \end{array} \]
    7. Add Preprocessing

    Alternative 2: 93.5% accurate, 6.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\\ {\left(t\_1 \cdot t\_1\right)}^{\left(-c\_p \cdot 0.5\right)} \end{array} \end{array} \]
    (FPCore (c_p c_n t s)
     :precision binary64
     (let* ((t_1 (fma s (fma s (fma s -0.16666666666666666 0.5) -1.0) 2.0)))
       (pow (* t_1 t_1) (- (* c_p 0.5)))))
    double code(double c_p, double c_n, double t, double s) {
    	double t_1 = fma(s, fma(s, fma(s, -0.16666666666666666, 0.5), -1.0), 2.0);
    	return pow((t_1 * t_1), -(c_p * 0.5));
    }
    
    function code(c_p, c_n, t, s)
    	t_1 = fma(s, fma(s, fma(s, -0.16666666666666666, 0.5), -1.0), 2.0)
    	return Float64(t_1 * t_1) ^ Float64(-Float64(c_p * 0.5))
    end
    
    code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(s * N[(s * N[(s * -0.16666666666666666 + 0.5), $MachinePrecision] + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]}, N[Power[N[(t$95$1 * t$95$1), $MachinePrecision], (-N[(c$95$p * 0.5), $MachinePrecision])], $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\\
    {\left(t\_1 \cdot t\_1\right)}^{\left(-c\_p \cdot 0.5\right)}
    \end{array}
    \end{array}
    
    Derivation
    1. Initial program 92.6%

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

      \[\leadsto \frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    4. Step-by-step derivation
      1. Simplified93.8%

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

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

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

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

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

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

          \[\leadsto {\left(\frac{1}{1 + \color{blue}{e^{-1 \cdot s}}}\right)}^{c\_p} \]
        6. neg-mul-1N/A

          \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{c\_p} \]
        7. lower-neg.f6493.4

          \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{-s}}}\right)}^{c\_p} \]
      4. Simplified93.4%

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

        \[\leadsto {\left(\frac{1}{\color{blue}{2 + s \cdot \left(s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1\right)}}\right)}^{c\_p} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto {\left(\frac{1}{\color{blue}{s \cdot \left(s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1\right) + 2}}\right)}^{c\_p} \]
        2. lower-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1, 2\right)}}\right)}^{c\_p} \]
        3. sub-negN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) + \left(\mathsf{neg}\left(1\right)\right)}, 2\right)}\right)}^{c\_p} \]
        4. metadata-evalN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) + \color{blue}{-1}, 2\right)}\right)}^{c\_p} \]
        5. lower-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(s, \frac{1}{2} + \frac{-1}{6} \cdot s, -1\right)}, 2\right)}\right)}^{c\_p} \]
        6. +-commutativeN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{\frac{-1}{6} \cdot s + \frac{1}{2}}, -1\right), 2\right)}\right)}^{c\_p} \]
        7. *-commutativeN/A

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{s \cdot \frac{-1}{6}} + \frac{1}{2}, -1\right), 2\right)}\right)}^{c\_p} \]
        8. lower-fma.f6494.5

          \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(s, -0.16666666666666666, 0.5\right)}, -1\right), 2\right)}\right)}^{c\_p} \]
      7. Simplified94.5%

        \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)}}\right)}^{c\_p} \]
      8. Step-by-step derivation
        1. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{s \cdot \left(s \cdot \color{blue}{\mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right)} + -1\right) + 2}\right)}^{c\_p} \]
        2. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{s \cdot \color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right)} + 2}\right)}^{c\_p} \]
        3. lift-fma.f64N/A

          \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}}\right)}^{c\_p} \]
        4. lift-/.f64N/A

          \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{c\_p} \]
        5. sqr-powN/A

          \[\leadsto \color{blue}{{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)}} \]
        6. lift-/.f64N/A

          \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        7. inv-powN/A

          \[\leadsto {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        8. pow-powN/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
        9. lift-/.f64N/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
        10. inv-powN/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
        11. pow-powN/A

          \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
        12. pow-prod-downN/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
        13. lower-pow.f64N/A

          \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{-1}{6}, \frac{1}{2}\right), -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
      9. Applied egg-rr95.6%

        \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(s, \mathsf{fma}\left(s, -0.16666666666666666, 0.5\right), -1\right), 2\right)\right)}^{\left(-c\_p \cdot 0.5\right)}} \]
      10. Add Preprocessing

      Alternative 3: 93.3% accurate, 6.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\\ {\left(t\_1 \cdot t\_1\right)}^{\left(-c\_p \cdot 0.5\right)} \end{array} \end{array} \]
      (FPCore (c_p c_n t s)
       :precision binary64
       (let* ((t_1 (fma s (fma s 0.5 -1.0) 2.0))) (pow (* t_1 t_1) (- (* c_p 0.5)))))
      double code(double c_p, double c_n, double t, double s) {
      	double t_1 = fma(s, fma(s, 0.5, -1.0), 2.0);
      	return pow((t_1 * t_1), -(c_p * 0.5));
      }
      
      function code(c_p, c_n, t, s)
      	t_1 = fma(s, fma(s, 0.5, -1.0), 2.0)
      	return Float64(t_1 * t_1) ^ Float64(-Float64(c_p * 0.5))
      end
      
      code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(s * N[(s * 0.5 + -1.0), $MachinePrecision] + 2.0), $MachinePrecision]}, N[Power[N[(t$95$1 * t$95$1), $MachinePrecision], (-N[(c$95$p * 0.5), $MachinePrecision])], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := \mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\\
      {\left(t\_1 \cdot t\_1\right)}^{\left(-c\_p \cdot 0.5\right)}
      \end{array}
      \end{array}
      
      Derivation
      1. Initial program 92.6%

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

        \[\leadsto \frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
      4. Step-by-step derivation
        1. Simplified93.8%

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

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

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

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

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

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

            \[\leadsto {\left(\frac{1}{1 + \color{blue}{e^{-1 \cdot s}}}\right)}^{c\_p} \]
          6. neg-mul-1N/A

            \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{c\_p} \]
          7. lower-neg.f6493.4

            \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{-s}}}\right)}^{c\_p} \]
        4. Simplified93.4%

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

          \[\leadsto {\left(\frac{1}{\color{blue}{2 + s \cdot \left(\frac{1}{2} \cdot s - 1\right)}}\right)}^{c\_p} \]
        6. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto {\left(\frac{1}{\color{blue}{s \cdot \left(\frac{1}{2} \cdot s - 1\right) + 2}}\right)}^{c\_p} \]
          2. lower-fma.f64N/A

            \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \frac{1}{2} \cdot s - 1, 2\right)}}\right)}^{c\_p} \]
          3. sub-negN/A

            \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\frac{1}{2} \cdot s + \left(\mathsf{neg}\left(1\right)\right)}, 2\right)}\right)}^{c\_p} \]
          4. metadata-evalN/A

            \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \frac{1}{2} \cdot s + \color{blue}{-1}, 2\right)}\right)}^{c\_p} \]
          5. lower-fma.f6494.5

            \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(0.5, s, -1\right)}, 2\right)}\right)}^{c\_p} \]
        7. Simplified94.5%

          \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(0.5, s, -1\right), 2\right)}}\right)}^{c\_p} \]
        8. Step-by-step derivation
          1. lift-fma.f64N/A

            \[\leadsto {\left(\frac{1}{s \cdot \color{blue}{\mathsf{fma}\left(\frac{1}{2}, s, -1\right)} + 2}\right)}^{c\_p} \]
          2. lift-fma.f64N/A

            \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}}\right)}^{c\_p} \]
          3. lift-/.f64N/A

            \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}}^{c\_p} \]
          4. sqr-powN/A

            \[\leadsto \color{blue}{{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)}} \]
          5. lift-/.f64N/A

            \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
          6. inv-powN/A

            \[\leadsto {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
          7. pow-powN/A

            \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \cdot {\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}^{\left(\frac{c\_p}{2}\right)} \]
          8. lift-/.f64N/A

            \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
          9. inv-powN/A

            \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{-1}\right)}}^{\left(\frac{c\_p}{2}\right)} \]
          10. pow-powN/A

            \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)} \cdot \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
          11. pow-prod-downN/A

            \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
          12. lower-pow.f64N/A

            \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right) \cdot \mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot \frac{c\_p}{2}\right)}} \]
        9. Applied egg-rr94.9%

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

        Alternative 4: 92.8% accurate, 7.7× speedup?

        \[\begin{array}{l} \\ {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\right)}^{\left(-c\_p\right)} \end{array} \]
        (FPCore (c_p c_n t s)
         :precision binary64
         (pow (fma s (fma s 0.5 -1.0) 2.0) (- c_p)))
        double code(double c_p, double c_n, double t, double s) {
        	return pow(fma(s, fma(s, 0.5, -1.0), 2.0), -c_p);
        }
        
        function code(c_p, c_n, t, s)
        	return fma(s, fma(s, 0.5, -1.0), 2.0) ^ Float64(-c_p)
        end
        
        code[c$95$p_, c$95$n_, t_, s_] := N[Power[N[(s * N[(s * 0.5 + -1.0), $MachinePrecision] + 2.0), $MachinePrecision], (-c$95$p)], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\right)}^{\left(-c\_p\right)}
        \end{array}
        
        Derivation
        1. Initial program 92.6%

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

          \[\leadsto \frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
        4. Step-by-step derivation
          1. Simplified93.8%

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

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

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

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

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

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

              \[\leadsto {\left(\frac{1}{1 + \color{blue}{e^{-1 \cdot s}}}\right)}^{c\_p} \]
            6. neg-mul-1N/A

              \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{c\_p} \]
            7. lower-neg.f6493.4

              \[\leadsto {\left(\frac{1}{1 + e^{\color{blue}{-s}}}\right)}^{c\_p} \]
          4. Simplified93.4%

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

            \[\leadsto {\left(\frac{1}{\color{blue}{2 + s \cdot \left(\frac{1}{2} \cdot s - 1\right)}}\right)}^{c\_p} \]
          6. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto {\left(\frac{1}{\color{blue}{s \cdot \left(\frac{1}{2} \cdot s - 1\right) + 2}}\right)}^{c\_p} \]
            2. lower-fma.f64N/A

              \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \frac{1}{2} \cdot s - 1, 2\right)}}\right)}^{c\_p} \]
            3. sub-negN/A

              \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\frac{1}{2} \cdot s + \left(\mathsf{neg}\left(1\right)\right)}, 2\right)}\right)}^{c\_p} \]
            4. metadata-evalN/A

              \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \frac{1}{2} \cdot s + \color{blue}{-1}, 2\right)}\right)}^{c\_p} \]
            5. lower-fma.f6494.5

              \[\leadsto {\left(\frac{1}{\mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(0.5, s, -1\right)}, 2\right)}\right)}^{c\_p} \]
          7. Simplified94.5%

            \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(0.5, s, -1\right), 2\right)}}\right)}^{c\_p} \]
          8. Step-by-step derivation
            1. lift-fma.f64N/A

              \[\leadsto {\left(\frac{1}{s \cdot \color{blue}{\mathsf{fma}\left(\frac{1}{2}, s, -1\right)} + 2}\right)}^{c\_p} \]
            2. lift-fma.f64N/A

              \[\leadsto {\left(\frac{1}{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}}\right)}^{c\_p} \]
            3. lift-/.f64N/A

              \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}}^{c\_p} \]
            4. lift-/.f64N/A

              \[\leadsto {\color{blue}{\left(\frac{1}{\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)}\right)}}^{c\_p} \]
            5. inv-powN/A

              \[\leadsto {\color{blue}{\left({\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{-1}\right)}}^{c\_p} \]
            6. pow-powN/A

              \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot c\_p\right)}} \]
            7. lower-pow.f64N/A

              \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(\frac{1}{2}, s, -1\right), 2\right)\right)}^{\left(-1 \cdot c\_p\right)}} \]
            8. lift-fma.f64N/A

              \[\leadsto {\left(\mathsf{fma}\left(s, \color{blue}{\frac{1}{2} \cdot s + -1}, 2\right)\right)}^{\left(-1 \cdot c\_p\right)} \]
            9. *-commutativeN/A

              \[\leadsto {\left(\mathsf{fma}\left(s, \color{blue}{s \cdot \frac{1}{2}} + -1, 2\right)\right)}^{\left(-1 \cdot c\_p\right)} \]
            10. lower-fma.f64N/A

              \[\leadsto {\left(\mathsf{fma}\left(s, \color{blue}{\mathsf{fma}\left(s, \frac{1}{2}, -1\right)}, 2\right)\right)}^{\left(-1 \cdot c\_p\right)} \]
            11. neg-mul-1N/A

              \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, \frac{1}{2}, -1\right), 2\right)\right)}^{\color{blue}{\left(\mathsf{neg}\left(c\_p\right)\right)}} \]
            12. lower-neg.f6494.5

              \[\leadsto {\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\right)}^{\color{blue}{\left(-c\_p\right)}} \]
          9. Applied egg-rr94.5%

            \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(s, \mathsf{fma}\left(s, 0.5, -1\right), 2\right)\right)}^{\left(-c\_p\right)}} \]
          10. Add Preprocessing

          Alternative 5: 94.4% accurate, 896.0× speedup?

          \[\begin{array}{l} \\ 1 \end{array} \]
          (FPCore (c_p c_n t s) :precision binary64 1.0)
          double code(double c_p, double c_n, double t, double s) {
          	return 1.0;
          }
          
          real(8) function code(c_p, c_n, t, s)
              real(8), intent (in) :: c_p
              real(8), intent (in) :: c_n
              real(8), intent (in) :: t
              real(8), intent (in) :: s
              code = 1.0d0
          end function
          
          public static double code(double c_p, double c_n, double t, double s) {
          	return 1.0;
          }
          
          def code(c_p, c_n, t, s):
          	return 1.0
          
          function code(c_p, c_n, t, s)
          	return 1.0
          end
          
          function tmp = code(c_p, c_n, t, s)
          	tmp = 1.0;
          end
          
          code[c$95$p_, c$95$n_, t_, s_] := 1.0
          
          \begin{array}{l}
          
          \\
          1
          \end{array}
          
          Derivation
          1. Initial program 92.6%

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
          5. Simplified92.7%

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

            \[\leadsto \color{blue}{1} \]
          7. Step-by-step derivation
            1. Simplified91.9%

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

            Developer Target 1: 96.6% 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 2024210 
            (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))))