Harley's example

Percentage Accurate: 90.6% → 98.6%
Time: 52.8s
Alternatives: 8
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 8 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: 90.6% 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: 98.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{-s}\\ \mathbf{if}\;-s \leq 200000000:\\ \;\;\;\;e^{\left(\log \left(1 - e^{-\mathsf{log1p}\left(t\_1\right)}\right) - \log \left(1 - e^{-\mathsf{log1p}\left(e^{-t}\right)}\right)\right) \cdot c\_n}\\ \mathbf{else}:\\ \;\;\;\;{\left({\left(\left(t\_1 + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (exp (- s))))
   (if (<= (- s) 200000000.0)
     (exp
      (*
       (-
        (log (- 1.0 (exp (- (log1p t_1)))))
        (log (- 1.0 (exp (- (log1p (exp (- t))))))))
       c_n))
     (pow (pow (* (+ t_1 1.0) (fma 0.25 t 0.5)) c_p) -1.0))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = exp(-s);
	double tmp;
	if (-s <= 200000000.0) {
		tmp = exp(((log((1.0 - exp(-log1p(t_1)))) - log((1.0 - exp(-log1p(exp(-t)))))) * c_n));
	} else {
		tmp = pow(pow(((t_1 + 1.0) * fma(0.25, t, 0.5)), c_p), -1.0);
	}
	return tmp;
}
function code(c_p, c_n, t, s)
	t_1 = exp(Float64(-s))
	tmp = 0.0
	if (Float64(-s) <= 200000000.0)
		tmp = exp(Float64(Float64(log(Float64(1.0 - exp(Float64(-log1p(t_1))))) - log(Float64(1.0 - exp(Float64(-log1p(exp(Float64(-t)))))))) * c_n));
	else
		tmp = (Float64(Float64(t_1 + 1.0) * fma(0.25, t, 0.5)) ^ c_p) ^ -1.0;
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[Exp[(-s)], $MachinePrecision]}, If[LessEqual[(-s), 200000000.0], N[Exp[N[(N[(N[Log[N[(1.0 - N[Exp[(-N[Log[1 + t$95$1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[Log[N[(1.0 - N[Exp[(-N[Log[1 + N[Exp[(-t)], $MachinePrecision]], $MachinePrecision])], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * c$95$n), $MachinePrecision]], $MachinePrecision], N[Power[N[Power[N[(N[(t$95$1 + 1.0), $MachinePrecision] * N[(0.25 * t + 0.5), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision], -1.0], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := e^{-s}\\
\mathbf{if}\;-s \leq 200000000:\\
\;\;\;\;e^{\left(\log \left(1 - e^{-\mathsf{log1p}\left(t\_1\right)}\right) - \log \left(1 - e^{-\mathsf{log1p}\left(e^{-t}\right)}\right)\right) \cdot c\_n}\\

\mathbf{else}:\\
\;\;\;\;{\left({\left(\left(t\_1 + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (neg.f64 s) < 2e8

    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. Add Preprocessing
    3. Applied rewrites94.9%

      \[\leadsto \color{blue}{e^{\mathsf{fma}\left(-\mathsf{log1p}\left(e^{-s}\right), c\_p, \mathsf{log1p}\left(-e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) \cdot c\_n\right) - \mathsf{fma}\left(-\mathsf{log1p}\left(e^{-t}\right), c\_p, \mathsf{log1p}\left(-e^{-\mathsf{log1p}\left(e^{-t}\right)}\right) \cdot c\_n\right)}} \]
    4. Taylor expanded in c_p around 0

      \[\leadsto e^{\color{blue}{c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right)}\right) - c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(t\right)}\right)\right)}\right)}} \]
    5. Applied rewrites99.6%

      \[\leadsto e^{\color{blue}{\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left(1 - e^{-\mathsf{log1p}\left(e^{-t}\right)}\right)\right) \cdot c\_n}} \]

    if 2e8 < (neg.f64 s)

    1. Initial program 50.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
      13. lower-neg.f6466.7

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
    5. Applied rewrites66.7%

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

      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
    7. Step-by-step derivation
      1. Applied rewrites66.7%

        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
      2. Step-by-step derivation
        1. Applied rewrites66.7%

          \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
        2. Step-by-step derivation
          1. Applied rewrites100.0%

            \[\leadsto \frac{1}{\color{blue}{{\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification99.6%

          \[\leadsto \begin{array}{l} \mathbf{if}\;-s \leq 200000000:\\ \;\;\;\;e^{\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left(1 - e^{-\mathsf{log1p}\left(e^{-t}\right)}\right)\right) \cdot c\_n}\\ \mathbf{else}:\\ \;\;\;\;{\left({\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\ \end{array} \]
        5. Add Preprocessing

        Alternative 2: 98.2% accurate, 2.8× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -740000000:\\ \;\;\;\;{\left({\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(\mathsf{fma}\left(s, -0.5, \log 0.5\right) - \log 0.5\right) \cdot c\_n}\\ \end{array} \end{array} \]
        (FPCore (c_p c_n t s)
         :precision binary64
         (if (<= s -740000000.0)
           (pow (pow (* (+ (exp (- s)) 1.0) (fma 0.25 t 0.5)) c_p) -1.0)
           (exp (* (- (fma s -0.5 (log 0.5)) (log 0.5)) c_n))))
        double code(double c_p, double c_n, double t, double s) {
        	double tmp;
        	if (s <= -740000000.0) {
        		tmp = pow(pow(((exp(-s) + 1.0) * fma(0.25, t, 0.5)), c_p), -1.0);
        	} else {
        		tmp = exp(((fma(s, -0.5, log(0.5)) - log(0.5)) * c_n));
        	}
        	return tmp;
        }
        
        function code(c_p, c_n, t, s)
        	tmp = 0.0
        	if (s <= -740000000.0)
        		tmp = (Float64(Float64(exp(Float64(-s)) + 1.0) * fma(0.25, t, 0.5)) ^ c_p) ^ -1.0;
        	else
        		tmp = exp(Float64(Float64(fma(s, -0.5, log(0.5)) - log(0.5)) * c_n));
        	end
        	return tmp
        end
        
        code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -740000000.0], N[Power[N[Power[N[(N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision] * N[(0.25 * t + 0.5), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision], -1.0], $MachinePrecision], N[Exp[N[(N[(N[(s * -0.5 + N[Log[0.5], $MachinePrecision]), $MachinePrecision] - N[Log[0.5], $MachinePrecision]), $MachinePrecision] * c$95$n), $MachinePrecision]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;s \leq -740000000:\\
        \;\;\;\;{\left({\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\
        
        \mathbf{else}:\\
        \;\;\;\;e^{\left(\mathsf{fma}\left(s, -0.5, \log 0.5\right) - \log 0.5\right) \cdot c\_n}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if s < -7.4e8

          1. Initial program 50.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
            13. lower-neg.f6466.7

              \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
          5. Applied rewrites66.7%

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

            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
          7. Step-by-step derivation
            1. Applied rewrites66.7%

              \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
            2. Step-by-step derivation
              1. Applied rewrites66.7%

                \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
              2. Step-by-step derivation
                1. Applied rewrites100.0%

                  \[\leadsto \frac{1}{\color{blue}{{\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]

                if -7.4e8 < s

                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. Add Preprocessing
                3. Applied rewrites94.9%

                  \[\leadsto \color{blue}{e^{\mathsf{fma}\left(-\mathsf{log1p}\left(e^{-s}\right), c\_p, \mathsf{log1p}\left(-e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) \cdot c\_n\right) - \mathsf{fma}\left(-\mathsf{log1p}\left(e^{-t}\right), c\_p, \mathsf{log1p}\left(-e^{-\mathsf{log1p}\left(e^{-t}\right)}\right) \cdot c\_n\right)}} \]
                4. Taylor expanded in c_p around 0

                  \[\leadsto e^{\color{blue}{c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right)}\right) - c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(t\right)}\right)\right)}\right)}} \]
                5. Applied rewrites99.6%

                  \[\leadsto e^{\color{blue}{\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left(1 - e^{-\mathsf{log1p}\left(e^{-t}\right)}\right)\right) \cdot c\_n}} \]
                6. Taylor expanded in t around 0

                  \[\leadsto e^{\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) - \log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right)\right) \cdot c\_n} \]
                7. Step-by-step derivation
                  1. Applied rewrites98.7%

                    \[\leadsto e^{\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right) - \log 0.5\right) \cdot c\_n} \]
                  2. Taylor expanded in s around 0

                    \[\leadsto e^{\left(\left(\log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right) + \frac{-1}{2} \cdot \frac{s \cdot e^{\mathsf{neg}\left(\log 2\right)}}{1 - e^{\mathsf{neg}\left(\log 2\right)}}\right) - \log \frac{1}{2}\right) \cdot c\_n} \]
                  3. Step-by-step derivation
                    1. Applied rewrites98.9%

                      \[\leadsto e^{\left(\mathsf{fma}\left(s \cdot 1, -0.5, \log 0.5\right) - \log 0.5\right) \cdot c\_n} \]
                  4. Recombined 2 regimes into one program.
                  5. Final simplification98.9%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;s \leq -740000000:\\ \;\;\;\;{\left({\left(\left(e^{-s} + 1\right) \cdot \mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(\mathsf{fma}\left(s, -0.5, \log 0.5\right) - \log 0.5\right) \cdot c\_n}\\ \end{array} \]
                  6. Add Preprocessing

                  Alternative 3: 94.1% accurate, 3.6× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -4 \cdot 10^{-30}:\\ \;\;\;\;\frac{{\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, s, 0.5\right) \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\ \end{array} \end{array} \]
                  (FPCore (c_p c_n t s)
                   :precision binary64
                   (if (<= s -4e-30)
                     (/
                      (pow (fma (- (* (fma -0.16666666666666666 s 0.5) s) 1.0) s 2.0) (- c_p))
                      (pow (fma 0.25 t 0.5) c_p))
                     (/ (pow 0.5 c_n) (pow (fma -0.25 t 0.5) c_n))))
                  double code(double c_p, double c_n, double t, double s) {
                  	double tmp;
                  	if (s <= -4e-30) {
                  		tmp = pow(fma(((fma(-0.16666666666666666, s, 0.5) * s) - 1.0), s, 2.0), -c_p) / pow(fma(0.25, t, 0.5), c_p);
                  	} else {
                  		tmp = pow(0.5, c_n) / pow(fma(-0.25, t, 0.5), c_n);
                  	}
                  	return tmp;
                  }
                  
                  function code(c_p, c_n, t, s)
                  	tmp = 0.0
                  	if (s <= -4e-30)
                  		tmp = Float64((fma(Float64(Float64(fma(-0.16666666666666666, s, 0.5) * s) - 1.0), s, 2.0) ^ Float64(-c_p)) / (fma(0.25, t, 0.5) ^ c_p));
                  	else
                  		tmp = Float64((0.5 ^ c_n) / (fma(-0.25, t, 0.5) ^ c_n));
                  	end
                  	return tmp
                  end
                  
                  code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -4e-30], N[(N[Power[N[(N[(N[(N[(-0.16666666666666666 * s + 0.5), $MachinePrecision] * s), $MachinePrecision] - 1.0), $MachinePrecision] * s + 2.0), $MachinePrecision], (-c$95$p)], $MachinePrecision] / N[Power[N[(0.25 * t + 0.5), $MachinePrecision], c$95$p], $MachinePrecision]), $MachinePrecision], N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(-0.25 * t + 0.5), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;s \leq -4 \cdot 10^{-30}:\\
                  \;\;\;\;\frac{{\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, s, 0.5\right) \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if s < -4e-30

                    1. Initial program 68.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

                        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                      13. lower-neg.f6473.2

                        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                    5. Applied rewrites73.2%

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

                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
                    7. Step-by-step derivation
                      1. Applied rewrites73.2%

                        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
                      2. Step-by-step derivation
                        1. Applied rewrites73.2%

                          \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
                        2. Taylor expanded in s around 0

                          \[\leadsto \frac{{\left(2 + s \cdot \left(s \cdot \left(\frac{1}{2} + \frac{-1}{6} \cdot s\right) - 1\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{\frac{1}{4}}, t, \frac{1}{2}\right)\right)}^{c\_p}} \]
                        3. Step-by-step derivation
                          1. Applied rewrites87.0%

                            \[\leadsto \frac{{\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.16666666666666666, s, 0.5\right) \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{0.25}, t, 0.5\right)\right)}^{c\_p}} \]

                          if -4e-30 < s

                          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. lower--.f64N/A

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

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

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

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

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

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

                              \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                          5. Applied rewrites98.3%

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

                            \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
                          7. Step-by-step derivation
                            1. Applied rewrites98.3%

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

                              \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\left(\frac{1}{2} + \frac{-1}{4} \cdot t\right)}^{c\_n}} \]
                            3. Step-by-step derivation
                              1. Applied rewrites98.3%

                                \[\leadsto \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \]
                            4. Recombined 2 regimes into one program.
                            5. Add Preprocessing

                            Alternative 4: 93.9% accurate, 3.7× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;-s \leq 2 \cdot 10^{-107}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(\mathsf{fma}\left(0.5 \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\ \end{array} \end{array} \]
                            (FPCore (c_p c_n t s)
                             :precision binary64
                             (if (<= (- s) 2e-107)
                               (/ (pow 0.5 c_n) (pow (fma -0.25 t 0.5) c_n))
                               (/ (pow (fma (- (* 0.5 s) 1.0) s 2.0) (- c_p)) (pow (fma 0.25 t 0.5) c_p))))
                            double code(double c_p, double c_n, double t, double s) {
                            	double tmp;
                            	if (-s <= 2e-107) {
                            		tmp = pow(0.5, c_n) / pow(fma(-0.25, t, 0.5), c_n);
                            	} else {
                            		tmp = pow(fma(((0.5 * s) - 1.0), s, 2.0), -c_p) / pow(fma(0.25, t, 0.5), c_p);
                            	}
                            	return tmp;
                            }
                            
                            function code(c_p, c_n, t, s)
                            	tmp = 0.0
                            	if (Float64(-s) <= 2e-107)
                            		tmp = Float64((0.5 ^ c_n) / (fma(-0.25, t, 0.5) ^ c_n));
                            	else
                            		tmp = Float64((fma(Float64(Float64(0.5 * s) - 1.0), s, 2.0) ^ Float64(-c_p)) / (fma(0.25, t, 0.5) ^ c_p));
                            	end
                            	return tmp
                            end
                            
                            code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[(-s), 2e-107], N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(-0.25 * t + 0.5), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision], N[(N[Power[N[(N[(N[(0.5 * s), $MachinePrecision] - 1.0), $MachinePrecision] * s + 2.0), $MachinePrecision], (-c$95$p)], $MachinePrecision] / N[Power[N[(0.25 * t + 0.5), $MachinePrecision], c$95$p], $MachinePrecision]), $MachinePrecision]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;-s \leq 2 \cdot 10^{-107}:\\
                            \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;\frac{{\left(\mathsf{fma}\left(0.5 \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if (neg.f64 s) < 2e-107

                              1. Initial program 91.5%

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                              5. Applied rewrites98.0%

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

                                \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
                              7. Step-by-step derivation
                                1. Applied rewrites98.0%

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

                                  \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\left(\frac{1}{2} + \frac{-1}{4} \cdot t\right)}^{c\_n}} \]
                                3. Step-by-step derivation
                                  1. Applied rewrites98.0%

                                    \[\leadsto \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \]

                                  if 2e-107 < (neg.f64 s)

                                  1. Initial program 84.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                    13. lower-neg.f6487.1

                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                                  5. Applied rewrites87.1%

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

                                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
                                  7. Step-by-step derivation
                                    1. Applied rewrites87.1%

                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
                                    2. Step-by-step derivation
                                      1. Applied rewrites87.1%

                                        \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
                                      2. Taylor expanded in s around 0

                                        \[\leadsto \frac{{\left(2 + s \cdot \left(\frac{1}{2} \cdot s - 1\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{\frac{1}{4}}, t, \frac{1}{2}\right)\right)}^{c\_p}} \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites93.7%

                                          \[\leadsto \frac{{\left(\mathsf{fma}\left(0.5 \cdot s - 1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{0.25}, t, 0.5\right)\right)}^{c\_p}} \]
                                      4. Recombined 2 regimes into one program.
                                      5. Add Preprocessing

                                      Alternative 5: 93.6% accurate, 3.8× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -4 \cdot 10^{-30}:\\ \;\;\;\;\frac{{\left(\mathsf{fma}\left(-1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\ \end{array} \end{array} \]
                                      (FPCore (c_p c_n t s)
                                       :precision binary64
                                       (if (<= s -4e-30)
                                         (/ (pow (fma -1.0 s 2.0) (- c_p)) (pow (fma 0.25 t 0.5) c_p))
                                         (/ (pow 0.5 c_n) (pow (fma -0.25 t 0.5) c_n))))
                                      double code(double c_p, double c_n, double t, double s) {
                                      	double tmp;
                                      	if (s <= -4e-30) {
                                      		tmp = pow(fma(-1.0, s, 2.0), -c_p) / pow(fma(0.25, t, 0.5), c_p);
                                      	} else {
                                      		tmp = pow(0.5, c_n) / pow(fma(-0.25, t, 0.5), c_n);
                                      	}
                                      	return tmp;
                                      }
                                      
                                      function code(c_p, c_n, t, s)
                                      	tmp = 0.0
                                      	if (s <= -4e-30)
                                      		tmp = Float64((fma(-1.0, s, 2.0) ^ Float64(-c_p)) / (fma(0.25, t, 0.5) ^ c_p));
                                      	else
                                      		tmp = Float64((0.5 ^ c_n) / (fma(-0.25, t, 0.5) ^ c_n));
                                      	end
                                      	return tmp
                                      end
                                      
                                      code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -4e-30], N[(N[Power[N[(-1.0 * s + 2.0), $MachinePrecision], (-c$95$p)], $MachinePrecision] / N[Power[N[(0.25 * t + 0.5), $MachinePrecision], c$95$p], $MachinePrecision]), $MachinePrecision], N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(-0.25 * t + 0.5), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;s \leq -4 \cdot 10^{-30}:\\
                                      \;\;\;\;\frac{{\left(\mathsf{fma}\left(-1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\
                                      
                                      \mathbf{else}:\\
                                      \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if s < -4e-30

                                        1. Initial program 68.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                          13. lower-neg.f6473.2

                                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                                        5. Applied rewrites73.2%

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

                                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
                                        7. Step-by-step derivation
                                          1. Applied rewrites73.2%

                                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
                                          2. Step-by-step derivation
                                            1. Applied rewrites73.2%

                                              \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
                                            2. Taylor expanded in s around 0

                                              \[\leadsto \frac{{\left(2 + -1 \cdot s\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{\frac{1}{4}}, t, \frac{1}{2}\right)\right)}^{c\_p}} \]
                                            3. Step-by-step derivation
                                              1. Applied rewrites87.0%

                                                \[\leadsto \frac{{\left(\mathsf{fma}\left(-1, s, 2\right)\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{0.25}, t, 0.5\right)\right)}^{c\_p}} \]

                                              if -4e-30 < s

                                              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. lower--.f64N/A

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

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

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

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

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

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

                                                  \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                                              5. Applied rewrites98.3%

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

                                                \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
                                              7. Step-by-step derivation
                                                1. Applied rewrites98.3%

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

                                                  \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\left(\frac{1}{2} + \frac{-1}{4} \cdot t\right)}^{c\_n}} \]
                                                3. Step-by-step derivation
                                                  1. Applied rewrites98.3%

                                                    \[\leadsto \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \]
                                                4. Recombined 2 regimes into one program.
                                                5. Add Preprocessing

                                                Alternative 6: 94.0% accurate, 3.9× speedup?

                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;-t \leq -5 \cdot 10^{-140}:\\ \;\;\;\;\frac{{2}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\ \end{array} \end{array} \]
                                                (FPCore (c_p c_n t s)
                                                 :precision binary64
                                                 (if (<= (- t) -5e-140)
                                                   (/ (pow 2.0 (- c_p)) (pow (fma 0.25 t 0.5) c_p))
                                                   (/ (pow 0.5 c_n) (pow (fma -0.25 t 0.5) c_n))))
                                                double code(double c_p, double c_n, double t, double s) {
                                                	double tmp;
                                                	if (-t <= -5e-140) {
                                                		tmp = pow(2.0, -c_p) / pow(fma(0.25, t, 0.5), c_p);
                                                	} else {
                                                		tmp = pow(0.5, c_n) / pow(fma(-0.25, t, 0.5), c_n);
                                                	}
                                                	return tmp;
                                                }
                                                
                                                function code(c_p, c_n, t, s)
                                                	tmp = 0.0
                                                	if (Float64(-t) <= -5e-140)
                                                		tmp = Float64((2.0 ^ Float64(-c_p)) / (fma(0.25, t, 0.5) ^ c_p));
                                                	else
                                                		tmp = Float64((0.5 ^ c_n) / (fma(-0.25, t, 0.5) ^ c_n));
                                                	end
                                                	return tmp
                                                end
                                                
                                                code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[(-t), -5e-140], N[(N[Power[2.0, (-c$95$p)], $MachinePrecision] / N[Power[N[(0.25 * t + 0.5), $MachinePrecision], c$95$p], $MachinePrecision]), $MachinePrecision], N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(-0.25 * t + 0.5), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]]
                                                
                                                \begin{array}{l}
                                                
                                                \\
                                                \begin{array}{l}
                                                \mathbf{if}\;-t \leq -5 \cdot 10^{-140}:\\
                                                \;\;\;\;\frac{{2}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}\\
                                                
                                                \mathbf{else}:\\
                                                \;\;\;\;\frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}\\
                                                
                                                
                                                \end{array}
                                                \end{array}
                                                
                                                Derivation
                                                1. Split input into 2 regimes
                                                2. if (neg.f64 t) < -5.00000000000000015e-140

                                                  1. Initial program 91.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                                    13. lower-neg.f6495.0

                                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                                                  5. Applied rewrites95.0%

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

                                                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{2} + \frac{1}{4} \cdot t\right)}^{c\_p}} \]
                                                  7. Step-by-step derivation
                                                    1. Applied rewrites95.0%

                                                      \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}} \]
                                                    2. Step-by-step derivation
                                                      1. Applied rewrites95.0%

                                                        \[\leadsto \color{blue}{\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(0.25, t, 0.5\right)\right)}^{c\_p}}} \]
                                                      2. Taylor expanded in s around 0

                                                        \[\leadsto \frac{{2}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{\frac{1}{4}}, t, \frac{1}{2}\right)\right)}^{c\_p}} \]
                                                      3. Step-by-step derivation
                                                        1. Applied rewrites98.3%

                                                          \[\leadsto \frac{{2}^{\left(-c\_p\right)}}{{\left(\mathsf{fma}\left(\color{blue}{0.25}, t, 0.5\right)\right)}^{c\_p}} \]

                                                        if -5.00000000000000015e-140 < (neg.f64 t)

                                                        1. Initial program 89.5%

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

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

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

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

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

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

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

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

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

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

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

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

                                                          \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
                                                        7. Step-by-step derivation
                                                          1. Applied rewrites95.7%

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

                                                            \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\left(\frac{1}{2} + \frac{-1}{4} \cdot t\right)}^{c\_n}} \]
                                                          3. Step-by-step derivation
                                                            1. Applied rewrites95.7%

                                                              \[\leadsto \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \]
                                                          4. Recombined 2 regimes into one program.
                                                          5. Add Preprocessing

                                                          Alternative 7: 93.2% accurate, 4.1× speedup?

                                                          \[\begin{array}{l} \\ \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \end{array} \]
                                                          (FPCore (c_p c_n t s)
                                                           :precision binary64
                                                           (/ (pow 0.5 c_n) (pow (fma -0.25 t 0.5) c_n)))
                                                          double code(double c_p, double c_n, double t, double s) {
                                                          	return pow(0.5, c_n) / pow(fma(-0.25, t, 0.5), c_n);
                                                          }
                                                          
                                                          function code(c_p, c_n, t, s)
                                                          	return Float64((0.5 ^ c_n) / (fma(-0.25, t, 0.5) ^ c_n))
                                                          end
                                                          
                                                          code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[Power[N[(-0.25 * t + 0.5), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]
                                                          
                                                          \begin{array}{l}
                                                          
                                                          \\
                                                          \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}}
                                                          \end{array}
                                                          
                                                          Derivation
                                                          1. Initial program 90.0%

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

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

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

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

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

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

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

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

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

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

                                                              \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                                                          5. Applied rewrites95.8%

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

                                                            \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\color{blue}{\left(1 - \frac{1}{e^{-t} + 1}\right)}}^{c\_n}} \]
                                                          7. Step-by-step derivation
                                                            1. Applied rewrites95.5%

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

                                                              \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{{\left(\frac{1}{2} + \frac{-1}{4} \cdot t\right)}^{c\_n}} \]
                                                            3. Step-by-step derivation
                                                              1. Applied rewrites94.7%

                                                                \[\leadsto \frac{{0.5}^{c\_n}}{{\left(\mathsf{fma}\left(-0.25, t, 0.5\right)\right)}^{c\_n}} \]
                                                              2. Add Preprocessing

                                                              Alternative 8: 93.9% 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 90.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                                                13. lower-neg.f6490.5

                                                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                                                              5. Applied rewrites90.5%

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

                                                                \[\leadsto 1 \]
                                                              7. Step-by-step derivation
                                                                1. Applied rewrites94.4%

                                                                  \[\leadsto 1 \]
                                                                2. Add Preprocessing

                                                                Developer Target 1: 96.4% accurate, 1.4× speedup?

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

                                                                Reproduce

                                                                ?
                                                                herbie shell --seed 2024333 
                                                                (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))))