Harley's example

Percentage Accurate: 91.1% → 97.5%
Time: 1.1min
Alternatives: 4
Speedup: 896.0×

Specification

?
\[0 < c\_p \land 0 < c\_n\]
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{1 + e^{-t}}\\ t_2 := \frac{1}{1 + e^{-s}}\\ \frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}} \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
   (/
    (* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
    (* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + exp(-t));
	double t_2 = 1.0 / (1.0 + exp(-s));
	return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 4 alternatives:

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

Initial Program: 91.1% 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));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(c_p, c_n, t, s)
use fmin_fmax_functions
    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: 97.5% accurate, 3.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -330000:\\ \;\;\;\;e^{\left(\left(s \cdot s\right) \cdot -0.125\right) \cdot c\_p - \log 0.5 \cdot c\_p}\\ \mathbf{elif}\;s \leq 10^{-50}:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{1 \cdot 1}\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (if (<= s -330000.0)
   (exp (- (* (* (* s s) -0.125) c_p) (* (log 0.5) c_p)))
   (if (<= s 1e-50) 1.0 (/ (pow 0.5 c_n) (* 1.0 1.0)))))
double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (s <= -330000.0) {
		tmp = exp(((((s * s) * -0.125) * c_p) - (log(0.5) * c_p)));
	} else if (s <= 1e-50) {
		tmp = 1.0;
	} else {
		tmp = pow(0.5, c_n) / (1.0 * 1.0);
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(c_p, c_n, t, s)
use fmin_fmax_functions
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    real(8) :: tmp
    if (s <= (-330000.0d0)) then
        tmp = exp(((((s * s) * (-0.125d0)) * c_p) - (log(0.5d0) * c_p)))
    else if (s <= 1d-50) then
        tmp = 1.0d0
    else
        tmp = (0.5d0 ** c_n) / (1.0d0 * 1.0d0)
    end if
    code = tmp
end function
public static double code(double c_p, double c_n, double t, double s) {
	double tmp;
	if (s <= -330000.0) {
		tmp = Math.exp(((((s * s) * -0.125) * c_p) - (Math.log(0.5) * c_p)));
	} else if (s <= 1e-50) {
		tmp = 1.0;
	} else {
		tmp = Math.pow(0.5, c_n) / (1.0 * 1.0);
	}
	return tmp;
}
def code(c_p, c_n, t, s):
	tmp = 0
	if s <= -330000.0:
		tmp = math.exp(((((s * s) * -0.125) * c_p) - (math.log(0.5) * c_p)))
	elif s <= 1e-50:
		tmp = 1.0
	else:
		tmp = math.pow(0.5, c_n) / (1.0 * 1.0)
	return tmp
function code(c_p, c_n, t, s)
	tmp = 0.0
	if (s <= -330000.0)
		tmp = exp(Float64(Float64(Float64(Float64(s * s) * -0.125) * c_p) - Float64(log(0.5) * c_p)));
	elseif (s <= 1e-50)
		tmp = 1.0;
	else
		tmp = Float64((0.5 ^ c_n) / Float64(1.0 * 1.0));
	end
	return tmp
end
function tmp_2 = code(c_p, c_n, t, s)
	tmp = 0.0;
	if (s <= -330000.0)
		tmp = exp(((((s * s) * -0.125) * c_p) - (log(0.5) * c_p)));
	elseif (s <= 1e-50)
		tmp = 1.0;
	else
		tmp = (0.5 ^ c_n) / (1.0 * 1.0);
	end
	tmp_2 = tmp;
end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -330000.0], N[Exp[N[(N[(N[(N[(s * s), $MachinePrecision] * -0.125), $MachinePrecision] * c$95$p), $MachinePrecision] - N[(N[Log[0.5], $MachinePrecision] * c$95$p), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], If[LessEqual[s, 1e-50], 1.0, N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[(1.0 * 1.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;s \leq -330000:\\
\;\;\;\;e^{\left(\left(s \cdot s\right) \cdot -0.125\right) \cdot c\_p - \log 0.5 \cdot c\_p}\\

\mathbf{elif}\;s \leq 10^{-50}:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\frac{{0.5}^{c\_n}}{1 \cdot 1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if s < -3.3e5

    1. Initial program 80.0%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    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. pow-to-expN/A

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

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

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

        \[\leadsto \frac{e^{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}{e^{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
      5. div-expN/A

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

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

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

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

      \[\leadsto e^{\left(s \cdot \left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
    7. Step-by-step derivation
      1. lower--.f64N/A

        \[\leadsto e^{\left(s \cdot \left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
      2. *-commutativeN/A

        \[\leadsto e^{\left(\left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
      3. lower-*.f64N/A

        \[\leadsto e^{\left(\left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
      4. +-commutativeN/A

        \[\leadsto e^{\left(\left(\frac{-1}{8} \cdot s + \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
      5. lower-fma.f64N/A

        \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
      6. lower-log.f64100.0

        \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
    8. Applied rewrites100.0%

      \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
    9. Taylor expanded in t around 0

      \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-1 \cdot \log 2\right) \cdot c\_p} \]
    10. Step-by-step derivation
      1. log-pow-revN/A

        \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \log \left({2}^{-1}\right) \cdot c\_p} \]
      2. metadata-evalN/A

        \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
      3. lower-log.f64100.0

        \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]
    11. Applied rewrites100.0%

      \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]
    12. Taylor expanded in s around inf

      \[\leadsto e^{\left(\frac{-1}{8} \cdot {s}^{2}\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
    13. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto e^{\left({s}^{2} \cdot \frac{-1}{8}\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
      2. lower-*.f64N/A

        \[\leadsto e^{\left({s}^{2} \cdot \frac{-1}{8}\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
      3. unpow2N/A

        \[\leadsto e^{\left(\left(s \cdot s\right) \cdot \frac{-1}{8}\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
      4. lower-*.f64100.0

        \[\leadsto e^{\left(\left(s \cdot s\right) \cdot -0.125\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]
    14. Applied rewrites100.0%

      \[\leadsto e^{\left(\left(s \cdot s\right) \cdot -0.125\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]

    if -3.3e5 < s < 1.00000000000000001e-50

    1. Initial program 92.3%

      \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
    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. Applied rewrites96.1%

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

      \[\leadsto 1 \]
    6. Step-by-step derivation
      1. Applied rewrites99.6%

        \[\leadsto 1 \]

      if 1.00000000000000001e-50 < s

      1. Initial program 65.2%

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

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

          \[\leadsto \frac{{\frac{1}{2}}^{c\_p} \cdot \color{blue}{{\frac{1}{2}}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
        2. pow-prod-upN/A

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

          \[\leadsto \frac{{\frac{1}{2}}^{\color{blue}{\left(c\_p + c\_n\right)}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
        4. lower-+.f6470.0

          \[\leadsto \frac{{0.5}^{\left(c\_p + \color{blue}{c\_n}\right)}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
      5. Applied rewrites70.0%

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

        \[\leadsto \frac{{\frac{1}{2}}^{\left(c\_p + c\_n\right)}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
      7. Step-by-step derivation
        1. Applied rewrites85.0%

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

          \[\leadsto \frac{{\frac{1}{2}}^{\left(c\_p + c\_n\right)}}{1 \cdot \color{blue}{1}} \]
        3. Step-by-step derivation
          1. Applied rewrites100.0%

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

            \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{1 \cdot 1} \]
          3. Step-by-step derivation
            1. Applied rewrites100.0%

              \[\leadsto \frac{{0.5}^{c\_n}}{1 \cdot 1} \]
          4. Recombined 3 regimes into one program.
          5. Add Preprocessing

          Alternative 2: 97.9% accurate, 2.7× speedup?

          \[\begin{array}{l} \\ e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p} \end{array} \]
          (FPCore (c_p c_n t s)
           :precision binary64
           (exp (- (* (- (* (fma -0.125 s 0.5) s) (log 2.0)) c_p) (* (log 0.5) c_p))))
          double code(double c_p, double c_n, double t, double s) {
          	return exp(((((fma(-0.125, s, 0.5) * s) - log(2.0)) * c_p) - (log(0.5) * c_p)));
          }
          
          function code(c_p, c_n, t, s)
          	return exp(Float64(Float64(Float64(Float64(fma(-0.125, s, 0.5) * s) - log(2.0)) * c_p) - Float64(log(0.5) * c_p)))
          end
          
          code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(N[(N[(N[(N[(-0.125 * s + 0.5), $MachinePrecision] * s), $MachinePrecision] - N[Log[2.0], $MachinePrecision]), $MachinePrecision] * c$95$p), $MachinePrecision] - N[(N[Log[0.5], $MachinePrecision] * c$95$p), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p}
          \end{array}
          
          Derivation
          1. Initial program 89.9%

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

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

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

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

              \[\leadsto \frac{e^{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}}{e^{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
            5. div-expN/A

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

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

              \[\leadsto e^{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)} \]
          5. Applied rewrites95.4%

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

            \[\leadsto e^{\left(s \cdot \left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
          7. Step-by-step derivation
            1. lower--.f64N/A

              \[\leadsto e^{\left(s \cdot \left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
            2. *-commutativeN/A

              \[\leadsto e^{\left(\left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
            3. lower-*.f64N/A

              \[\leadsto e^{\left(\left(\frac{1}{2} + \frac{-1}{8} \cdot s\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
            4. +-commutativeN/A

              \[\leadsto e^{\left(\left(\frac{-1}{8} \cdot s + \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
            5. lower-fma.f64N/A

              \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
            6. lower-log.f6496.9

              \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
          8. Applied rewrites96.9%

            \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \left(-\mathsf{log1p}\left(e^{-t}\right)\right) \cdot c\_p} \]
          9. Taylor expanded in t around 0

            \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \left(-1 \cdot \log 2\right) \cdot c\_p} \]
          10. Step-by-step derivation
            1. log-pow-revN/A

              \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \log \left({2}^{-1}\right) \cdot c\_p} \]
            2. metadata-evalN/A

              \[\leadsto e^{\left(\mathsf{fma}\left(\frac{-1}{8}, s, \frac{1}{2}\right) \cdot s - \log 2\right) \cdot c\_p - \log \frac{1}{2} \cdot c\_p} \]
            3. lower-log.f6498.5

              \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]
          11. Applied rewrites98.5%

            \[\leadsto e^{\left(\mathsf{fma}\left(-0.125, s, 0.5\right) \cdot s - \log 2\right) \cdot c\_p - \log 0.5 \cdot c\_p} \]
          12. Add Preprocessing

          Alternative 3: 95.6% accurate, 7.2× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq 10^{-50}:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\frac{{0.5}^{c\_n}}{1 \cdot 1}\\ \end{array} \end{array} \]
          (FPCore (c_p c_n t s)
           :precision binary64
           (if (<= s 1e-50) 1.0 (/ (pow 0.5 c_n) (* 1.0 1.0))))
          double code(double c_p, double c_n, double t, double s) {
          	double tmp;
          	if (s <= 1e-50) {
          		tmp = 1.0;
          	} else {
          		tmp = pow(0.5, c_n) / (1.0 * 1.0);
          	}
          	return tmp;
          }
          
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(c_p, c_n, t, s)
          use fmin_fmax_functions
              real(8), intent (in) :: c_p
              real(8), intent (in) :: c_n
              real(8), intent (in) :: t
              real(8), intent (in) :: s
              real(8) :: tmp
              if (s <= 1d-50) then
                  tmp = 1.0d0
              else
                  tmp = (0.5d0 ** c_n) / (1.0d0 * 1.0d0)
              end if
              code = tmp
          end function
          
          public static double code(double c_p, double c_n, double t, double s) {
          	double tmp;
          	if (s <= 1e-50) {
          		tmp = 1.0;
          	} else {
          		tmp = Math.pow(0.5, c_n) / (1.0 * 1.0);
          	}
          	return tmp;
          }
          
          def code(c_p, c_n, t, s):
          	tmp = 0
          	if s <= 1e-50:
          		tmp = 1.0
          	else:
          		tmp = math.pow(0.5, c_n) / (1.0 * 1.0)
          	return tmp
          
          function code(c_p, c_n, t, s)
          	tmp = 0.0
          	if (s <= 1e-50)
          		tmp = 1.0;
          	else
          		tmp = Float64((0.5 ^ c_n) / Float64(1.0 * 1.0));
          	end
          	return tmp
          end
          
          function tmp_2 = code(c_p, c_n, t, s)
          	tmp = 0.0;
          	if (s <= 1e-50)
          		tmp = 1.0;
          	else
          		tmp = (0.5 ^ c_n) / (1.0 * 1.0);
          	end
          	tmp_2 = tmp;
          end
          
          code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, 1e-50], 1.0, N[(N[Power[0.5, c$95$n], $MachinePrecision] / N[(1.0 * 1.0), $MachinePrecision]), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;s \leq 10^{-50}:\\
          \;\;\;\;1\\
          
          \mathbf{else}:\\
          \;\;\;\;\frac{{0.5}^{c\_n}}{1 \cdot 1}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if s < 1.00000000000000001e-50

            1. Initial program 92.0%

              \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
            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. Applied rewrites94.1%

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

              \[\leadsto 1 \]
            6. Step-by-step derivation
              1. Applied rewrites97.5%

                \[\leadsto 1 \]

              if 1.00000000000000001e-50 < s

              1. Initial program 65.2%

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

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

                  \[\leadsto \frac{{\frac{1}{2}}^{c\_p} \cdot \color{blue}{{\frac{1}{2}}^{c\_n}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
                2. pow-prod-upN/A

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

                  \[\leadsto \frac{{\frac{1}{2}}^{\color{blue}{\left(c\_p + c\_n\right)}}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
                4. lower-+.f6470.0

                  \[\leadsto \frac{{0.5}^{\left(c\_p + \color{blue}{c\_n}\right)}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
              5. Applied rewrites70.0%

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

                \[\leadsto \frac{{\frac{1}{2}}^{\left(c\_p + c\_n\right)}}{\color{blue}{1} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
              7. Step-by-step derivation
                1. Applied rewrites85.0%

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

                  \[\leadsto \frac{{\frac{1}{2}}^{\left(c\_p + c\_n\right)}}{1 \cdot \color{blue}{1}} \]
                3. Step-by-step derivation
                  1. Applied rewrites100.0%

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

                    \[\leadsto \frac{{\frac{1}{2}}^{c\_n}}{1 \cdot 1} \]
                  3. Step-by-step derivation
                    1. Applied rewrites100.0%

                      \[\leadsto \frac{{0.5}^{c\_n}}{1 \cdot 1} \]
                  4. Recombined 2 regimes into one program.
                  5. Add Preprocessing

                  Alternative 4: 94.3% 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;
                  }
                  
                  module fmin_fmax_functions
                      implicit none
                      private
                      public fmax
                      public fmin
                  
                      interface fmax
                          module procedure fmax88
                          module procedure fmax44
                          module procedure fmax84
                          module procedure fmax48
                      end interface
                      interface fmin
                          module procedure fmin88
                          module procedure fmin44
                          module procedure fmin84
                          module procedure fmin48
                      end interface
                  contains
                      real(8) function fmax88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmax44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmax84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmax48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                      end function
                      real(8) function fmin88(x, y) result (res)
                          real(8), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(4) function fmin44(x, y) result (res)
                          real(4), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                      end function
                      real(8) function fmin84(x, y) result(res)
                          real(8), intent (in) :: x
                          real(4), intent (in) :: y
                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                      end function
                      real(8) function fmin48(x, y) result(res)
                          real(4), intent (in) :: x
                          real(8), intent (in) :: y
                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                      end function
                  end module
                  
                  real(8) function code(c_p, c_n, t, s)
                  use fmin_fmax_functions
                      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 89.9%

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

                    \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                  4. Applied rewrites93.1%

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

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

                      \[\leadsto 1 \]
                    2. Add Preprocessing

                    Developer Target 1: 96.2% 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);
                    }
                    
                    module fmin_fmax_functions
                        implicit none
                        private
                        public fmax
                        public fmin
                    
                        interface fmax
                            module procedure fmax88
                            module procedure fmax44
                            module procedure fmax84
                            module procedure fmax48
                        end interface
                        interface fmin
                            module procedure fmin88
                            module procedure fmin44
                            module procedure fmin84
                            module procedure fmin48
                        end interface
                    contains
                        real(8) function fmax88(x, y) result (res)
                            real(8), intent (in) :: x
                            real(8), intent (in) :: y
                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                        end function
                        real(4) function fmax44(x, y) result (res)
                            real(4), intent (in) :: x
                            real(4), intent (in) :: y
                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                        end function
                        real(8) function fmax84(x, y) result(res)
                            real(8), intent (in) :: x
                            real(4), intent (in) :: y
                            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                        end function
                        real(8) function fmax48(x, y) result(res)
                            real(4), intent (in) :: x
                            real(8), intent (in) :: y
                            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                        end function
                        real(8) function fmin88(x, y) result (res)
                            real(8), intent (in) :: x
                            real(8), intent (in) :: y
                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                        end function
                        real(4) function fmin44(x, y) result (res)
                            real(4), intent (in) :: x
                            real(4), intent (in) :: y
                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                        end function
                        real(8) function fmin84(x, y) result(res)
                            real(8), intent (in) :: x
                            real(4), intent (in) :: y
                            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                        end function
                        real(8) function fmin48(x, y) result(res)
                            real(4), intent (in) :: x
                            real(8), intent (in) :: y
                            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                        end function
                    end module
                    
                    real(8) function code(c_p, c_n, t, s)
                    use fmin_fmax_functions
                        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 2025054 
                    (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))))