Logistic distribution

Percentage Accurate: 99.6% → 99.6%
Time: 12.8s
Alternatives: 8
Speedup: 2.0×

Specification

?
\[0 \leq s \land s \leq 1.0651631\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{\frac{-\left|x\right|}{s}}\\ t_1 := 1 + t\_0\\ \frac{t\_0}{\left(s \cdot t\_1\right) \cdot t\_1} \end{array} \end{array} \]
(FPCore (x s)
 :precision binary32
 (let* ((t_0 (exp (/ (- (fabs x)) s))) (t_1 (+ 1.0 t_0)))
   (/ t_0 (* (* s t_1) t_1))))
float code(float x, float s) {
	float t_0 = expf((-fabsf(x) / s));
	float t_1 = 1.0f + t_0;
	return t_0 / ((s * t_1) * t_1);
}
real(4) function code(x, s)
    real(4), intent (in) :: x
    real(4), intent (in) :: s
    real(4) :: t_0
    real(4) :: t_1
    t_0 = exp((-abs(x) / s))
    t_1 = 1.0e0 + t_0
    code = t_0 / ((s * t_1) * t_1)
end function
function code(x, s)
	t_0 = exp(Float32(Float32(-abs(x)) / s))
	t_1 = Float32(Float32(1.0) + t_0)
	return Float32(t_0 / Float32(Float32(s * t_1) * t_1))
end
function tmp = code(x, s)
	t_0 = exp((-abs(x) / s));
	t_1 = single(1.0) + t_0;
	tmp = t_0 / ((s * t_1) * t_1);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{\frac{-\left|x\right|}{s}}\\
t_1 := 1 + t\_0\\
\frac{t\_0}{\left(s \cdot t\_1\right) \cdot t\_1}
\end{array}
\end{array}

Sampling outcomes in binary32 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: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{\frac{-\left|x\right|}{s}}\\ t_1 := 1 + t\_0\\ \frac{t\_0}{\left(s \cdot t\_1\right) \cdot t\_1} \end{array} \end{array} \]
(FPCore (x s)
 :precision binary32
 (let* ((t_0 (exp (/ (- (fabs x)) s))) (t_1 (+ 1.0 t_0)))
   (/ t_0 (* (* s t_1) t_1))))
float code(float x, float s) {
	float t_0 = expf((-fabsf(x) / s));
	float t_1 = 1.0f + t_0;
	return t_0 / ((s * t_1) * t_1);
}
real(4) function code(x, s)
    real(4), intent (in) :: x
    real(4), intent (in) :: s
    real(4) :: t_0
    real(4) :: t_1
    t_0 = exp((-abs(x) / s))
    t_1 = 1.0e0 + t_0
    code = t_0 / ((s * t_1) * t_1)
end function
function code(x, s)
	t_0 = exp(Float32(Float32(-abs(x)) / s))
	t_1 = Float32(Float32(1.0) + t_0)
	return Float32(t_0 / Float32(Float32(s * t_1) * t_1))
end
function tmp = code(x, s)
	t_0 = exp((-abs(x) / s));
	t_1 = single(1.0) + t_0;
	tmp = t_0 / ((s * t_1) * t_1);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{\frac{-\left|x\right|}{s}}\\
t_1 := 1 + t\_0\\
\frac{t\_0}{\left(s \cdot t\_1\right) \cdot t\_1}
\end{array}
\end{array}

Alternative 1: 99.6% accurate, 1.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} t_0 := e^{\frac{x\_m}{-s}}\\ \frac{\frac{t\_0}{t\_0 + 1}}{s + \frac{s}{e^{\frac{x\_m}{s}}}} \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (let* ((t_0 (exp (/ x_m (- s)))))
   (/ (/ t_0 (+ t_0 1.0)) (+ s (/ s (exp (/ x_m s)))))))
x_m = fabs(x);
float code(float x_m, float s) {
	float t_0 = expf((x_m / -s));
	return (t_0 / (t_0 + 1.0f)) / (s + (s / expf((x_m / s))));
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: t_0
    t_0 = exp((x_m / -s))
    code = (t_0 / (t_0 + 1.0e0)) / (s + (s / exp((x_m / s))))
end function
x_m = abs(x)
function code(x_m, s)
	t_0 = exp(Float32(x_m / Float32(-s)))
	return Float32(Float32(t_0 / Float32(t_0 + Float32(1.0))) / Float32(s + Float32(s / exp(Float32(x_m / s)))))
end
x_m = abs(x);
function tmp = code(x_m, s)
	t_0 = exp((x_m / -s));
	tmp = (t_0 / (t_0 + single(1.0))) / (s + (s / exp((x_m / s))));
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
t_0 := e^{\frac{x\_m}{-s}}\\
\frac{\frac{t\_0}{t\_0 + 1}}{s + \frac{s}{e^{\frac{x\_m}{s}}}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    2. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    3. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
    5. distribute-lft-in99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
    6. *-rgt-identity99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
    7. +-commutative99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
  7. Simplified63.2%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
  8. Add Preprocessing

Alternative 2: 99.6% accurate, 2.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} t_0 := e^{\frac{x\_m}{-s}}\\ \frac{\frac{t\_0}{s}}{{\left(t\_0 + 1\right)}^{2}} \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (let* ((t_0 (exp (/ x_m (- s))))) (/ (/ t_0 s) (pow (+ t_0 1.0) 2.0))))
x_m = fabs(x);
float code(float x_m, float s) {
	float t_0 = expf((x_m / -s));
	return (t_0 / s) / powf((t_0 + 1.0f), 2.0f);
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: t_0
    t_0 = exp((x_m / -s))
    code = (t_0 / s) / ((t_0 + 1.0e0) ** 2.0e0)
end function
x_m = abs(x)
function code(x_m, s)
	t_0 = exp(Float32(x_m / Float32(-s)))
	return Float32(Float32(t_0 / s) / (Float32(t_0 + Float32(1.0)) ^ Float32(2.0)))
end
x_m = abs(x);
function tmp = code(x_m, s)
	t_0 = exp((x_m / -s));
	tmp = (t_0 / s) / ((t_0 + single(1.0)) ^ single(2.0));
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
t_0 := e^{\frac{x\_m}{-s}}\\
\frac{\frac{t\_0}{s}}{{\left(t\_0 + 1\right)}^{2}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\color{blue}{\left|-x\right|}}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. distribute-frac-neg99.8%

      \[\leadsto \frac{e^{\color{blue}{-\frac{\left|-x\right|}{s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    3. distribute-frac-neg299.8%

      \[\leadsto \frac{e^{\color{blue}{\frac{\left|-x\right|}{-s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\color{blue}{\left|x\right|}}{-s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    5. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    6. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    7. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    8. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{\left|x\right|}{-s}}}{s \cdot \left(\left(1 + e^{\frac{\left|x\right|}{-s}}\right) \cdot \left(1 + e^{\frac{\left|x\right|}{-s}}\right)\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{s \cdot {\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}}} \]
    2. mul-1-neg99.8%

      \[\leadsto \frac{\frac{e^{\color{blue}{-\frac{\left|x\right|}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    3. rec-exp99.8%

      \[\leadsto \frac{\frac{\color{blue}{\frac{1}{e^{\frac{\left|x\right|}{s}}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    4. rem-square-sqrt50.3%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    5. fabs-sqr50.3%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    6. rem-square-sqrt61.5%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\color{blue}{x}}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    7. rec-exp61.5%

      \[\leadsto \frac{\frac{\color{blue}{e^{-\frac{x}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    8. distribute-neg-frac261.5%

      \[\leadsto \frac{\frac{e^{\color{blue}{\frac{x}{-s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
  7. Simplified63.1%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{s}}{{\left(e^{\frac{x}{-s}} + 1\right)}^{2}}} \]
  8. Add Preprocessing

Alternative 3: 96.9% accurate, 2.8× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} t_0 := e^{\frac{x\_m}{-s}}\\ \frac{\frac{t\_0}{t\_0 + 1}}{s + \frac{s}{1 + \frac{x\_m}{s}}} \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (let* ((t_0 (exp (/ x_m (- s)))))
   (/ (/ t_0 (+ t_0 1.0)) (+ s (/ s (+ 1.0 (/ x_m s)))))))
x_m = fabs(x);
float code(float x_m, float s) {
	float t_0 = expf((x_m / -s));
	return (t_0 / (t_0 + 1.0f)) / (s + (s / (1.0f + (x_m / s))));
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: t_0
    t_0 = exp((x_m / -s))
    code = (t_0 / (t_0 + 1.0e0)) / (s + (s / (1.0e0 + (x_m / s))))
end function
x_m = abs(x)
function code(x_m, s)
	t_0 = exp(Float32(x_m / Float32(-s)))
	return Float32(Float32(t_0 / Float32(t_0 + Float32(1.0))) / Float32(s + Float32(s / Float32(Float32(1.0) + Float32(x_m / s)))))
end
x_m = abs(x);
function tmp = code(x_m, s)
	t_0 = exp((x_m / -s));
	tmp = (t_0 / (t_0 + single(1.0))) / (s + (s / (single(1.0) + (x_m / s))));
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
t_0 := e^{\frac{x\_m}{-s}}\\
\frac{\frac{t\_0}{t\_0 + 1}}{s + \frac{s}{1 + \frac{x\_m}{s}}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    2. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    3. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
    5. distribute-lft-in99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
    6. *-rgt-identity99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
    7. +-commutative99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
  7. Simplified63.2%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
  8. Taylor expanded in x around 0 60.6%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{\color{blue}{1 + \frac{x}{s}}}} \]
  9. Step-by-step derivation
    1. +-commutative60.6%

      \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{\color{blue}{\frac{x}{s} + 1}}} \]
  10. Simplified60.6%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{\color{blue}{\frac{x}{s} + 1}}} \]
  11. Final simplification60.6%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{1 + \frac{x}{s}}} \]
  12. Add Preprocessing

Alternative 4: 95.1% accurate, 2.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} t_0 := e^{\frac{x\_m}{-s}}\\ \frac{t\_0 \cdot 0.5}{s \cdot \left(t\_0 + 1\right)} \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (let* ((t_0 (exp (/ x_m (- s))))) (/ (* t_0 0.5) (* s (+ t_0 1.0)))))
x_m = fabs(x);
float code(float x_m, float s) {
	float t_0 = expf((x_m / -s));
	return (t_0 * 0.5f) / (s * (t_0 + 1.0f));
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: t_0
    t_0 = exp((x_m / -s))
    code = (t_0 * 0.5e0) / (s * (t_0 + 1.0e0))
end function
x_m = abs(x)
function code(x_m, s)
	t_0 = exp(Float32(x_m / Float32(-s)))
	return Float32(Float32(t_0 * Float32(0.5)) / Float32(s * Float32(t_0 + Float32(1.0))))
end
x_m = abs(x);
function tmp = code(x_m, s)
	t_0 = exp((x_m / -s));
	tmp = (t_0 * single(0.5)) / (s * (t_0 + single(1.0)));
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
t_0 := e^{\frac{x\_m}{-s}}\\
\frac{t\_0 \cdot 0.5}{s \cdot \left(t\_0 + 1\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    2. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    3. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
    5. distribute-lft-in99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
    6. *-rgt-identity99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
    7. +-commutative99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
  7. Simplified63.2%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
  8. Taylor expanded in s around inf 59.1%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \color{blue}{s}} \]
  9. Taylor expanded in x around inf 59.1%

    \[\leadsto \color{blue}{0.5 \cdot \frac{e^{-1 \cdot \frac{x}{s}}}{s \cdot \left(1 + e^{-1 \cdot \frac{x}{s}}\right)}} \]
  10. Step-by-step derivation
    1. associate-*r/59.1%

      \[\leadsto \color{blue}{\frac{0.5 \cdot e^{-1 \cdot \frac{x}{s}}}{s \cdot \left(1 + e^{-1 \cdot \frac{x}{s}}\right)}} \]
    2. neg-mul-159.1%

      \[\leadsto \frac{0.5 \cdot e^{\color{blue}{-\frac{x}{s}}}}{s \cdot \left(1 + e^{-1 \cdot \frac{x}{s}}\right)} \]
    3. distribute-neg-frac259.1%

      \[\leadsto \frac{0.5 \cdot e^{\color{blue}{\frac{x}{-s}}}}{s \cdot \left(1 + e^{-1 \cdot \frac{x}{s}}\right)} \]
    4. neg-mul-159.1%

      \[\leadsto \frac{0.5 \cdot e^{\frac{x}{-s}}}{s \cdot \left(1 + e^{\color{blue}{-\frac{x}{s}}}\right)} \]
    5. distribute-neg-frac259.1%

      \[\leadsto \frac{0.5 \cdot e^{\frac{x}{-s}}}{s \cdot \left(1 + e^{\color{blue}{\frac{x}{-s}}}\right)} \]
  11. Simplified59.1%

    \[\leadsto \color{blue}{\frac{0.5 \cdot e^{\frac{x}{-s}}}{s \cdot \left(1 + e^{\frac{x}{-s}}\right)}} \]
  12. Final simplification59.1%

    \[\leadsto \frac{e^{\frac{x}{-s}} \cdot 0.5}{s \cdot \left(e^{\frac{x}{-s}} + 1\right)} \]
  13. Add Preprocessing

Alternative 5: 94.7% accurate, 5.7× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \frac{\frac{e^{\frac{x\_m}{-s}}}{s}}{4} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s) :precision binary32 (/ (/ (exp (/ x_m (- s))) s) 4.0))
x_m = fabs(x);
float code(float x_m, float s) {
	return (expf((x_m / -s)) / s) / 4.0f;
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    code = (exp((x_m / -s)) / s) / 4.0e0
end function
x_m = abs(x)
function code(x_m, s)
	return Float32(Float32(exp(Float32(x_m / Float32(-s))) / s) / Float32(4.0))
end
x_m = abs(x);
function tmp = code(x_m, s)
	tmp = (exp((x_m / -s)) / s) / single(4.0);
end
\begin{array}{l}
x_m = \left|x\right|

\\
\frac{\frac{e^{\frac{x\_m}{-s}}}{s}}{4}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\color{blue}{\left|-x\right|}}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. distribute-frac-neg99.8%

      \[\leadsto \frac{e^{\color{blue}{-\frac{\left|-x\right|}{s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    3. distribute-frac-neg299.8%

      \[\leadsto \frac{e^{\color{blue}{\frac{\left|-x\right|}{-s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\color{blue}{\left|x\right|}}{-s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    5. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    6. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    7. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    8. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{\left|x\right|}{-s}}}{s \cdot \left(\left(1 + e^{\frac{\left|x\right|}{-s}}\right) \cdot \left(1 + e^{\frac{\left|x\right|}{-s}}\right)\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{s \cdot {\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}}} \]
    2. mul-1-neg99.8%

      \[\leadsto \frac{\frac{e^{\color{blue}{-\frac{\left|x\right|}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    3. rec-exp99.8%

      \[\leadsto \frac{\frac{\color{blue}{\frac{1}{e^{\frac{\left|x\right|}{s}}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    4. rem-square-sqrt50.3%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\left|\color{blue}{\sqrt{x} \cdot \sqrt{x}}\right|}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    5. fabs-sqr50.3%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\color{blue}{\sqrt{x} \cdot \sqrt{x}}}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    6. rem-square-sqrt61.5%

      \[\leadsto \frac{\frac{\frac{1}{e^{\frac{\color{blue}{x}}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    7. rec-exp61.5%

      \[\leadsto \frac{\frac{\color{blue}{e^{-\frac{x}{s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
    8. distribute-neg-frac261.5%

      \[\leadsto \frac{\frac{e^{\color{blue}{\frac{x}{-s}}}}{s}}{{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right)}^{2}} \]
  7. Simplified63.1%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{s}}{{\left(e^{\frac{x}{-s}} + 1\right)}^{2}}} \]
  8. Taylor expanded in x around 0 59.9%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{s}}{\color{blue}{4}} \]
  9. Add Preprocessing

Alternative 6: 85.8% accurate, 23.8× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 1.000000031374395 \cdot 10^{-22}:\\ \;\;\;\;\frac{0.5 - \frac{x\_m}{s} \cdot 0.25}{s \cdot 2 + x\_m \cdot \left(\frac{x\_m}{s} \cdot 0.5 + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (if (<= x_m 1.000000031374395e-22)
   (/
    (- 0.5 (* (/ x_m s) 0.25))
    (+ (* s 2.0) (* x_m (+ (* (/ x_m s) 0.5) -1.0))))
   0.0))
x_m = fabs(x);
float code(float x_m, float s) {
	float tmp;
	if (x_m <= 1.000000031374395e-22f) {
		tmp = (0.5f - ((x_m / s) * 0.25f)) / ((s * 2.0f) + (x_m * (((x_m / s) * 0.5f) + -1.0f)));
	} else {
		tmp = 0.0f;
	}
	return tmp;
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: tmp
    if (x_m <= 1.000000031374395e-22) then
        tmp = (0.5e0 - ((x_m / s) * 0.25e0)) / ((s * 2.0e0) + (x_m * (((x_m / s) * 0.5e0) + (-1.0e0))))
    else
        tmp = 0.0e0
    end if
    code = tmp
end function
x_m = abs(x)
function code(x_m, s)
	tmp = Float32(0.0)
	if (x_m <= Float32(1.000000031374395e-22))
		tmp = Float32(Float32(Float32(0.5) - Float32(Float32(x_m / s) * Float32(0.25))) / Float32(Float32(s * Float32(2.0)) + Float32(x_m * Float32(Float32(Float32(x_m / s) * Float32(0.5)) + Float32(-1.0)))));
	else
		tmp = Float32(0.0);
	end
	return tmp
end
x_m = abs(x);
function tmp_2 = code(x_m, s)
	tmp = single(0.0);
	if (x_m <= single(1.000000031374395e-22))
		tmp = (single(0.5) - ((x_m / s) * single(0.25))) / ((s * single(2.0)) + (x_m * (((x_m / s) * single(0.5)) + single(-1.0))));
	else
		tmp = single(0.0);
	end
	tmp_2 = tmp;
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 1.000000031374395 \cdot 10^{-22}:\\
\;\;\;\;\frac{0.5 - \frac{x\_m}{s} \cdot 0.25}{s \cdot 2 + x\_m \cdot \left(\frac{x\_m}{s} \cdot 0.5 + -1\right)}\\

\mathbf{else}:\\
\;\;\;\;0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.00000003e-22

    1. Initial program 99.7%

      \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. Step-by-step derivation
      1. *-commutative99.7%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
      2. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
      3. +-commutative99.7%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
      4. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
      5. distribute-lft-in99.8%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
      6. *-rgt-identity99.8%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
      7. +-commutative99.8%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.8%

      \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    6. Step-by-step derivation
      1. associate-/r*99.8%

        \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
    7. Simplified38.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
    8. Taylor expanded in s around -inf 73.7%

      \[\leadsto \frac{\color{blue}{0.5 + -1 \cdot \frac{0.5 \cdot x - 0.25 \cdot x}{s}}}{s + \frac{s}{e^{\frac{x}{s}}}} \]
    9. Step-by-step derivation
      1. mul-1-neg73.7%

        \[\leadsto \frac{0.5 + \color{blue}{\left(-\frac{0.5 \cdot x - 0.25 \cdot x}{s}\right)}}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      2. distribute-rgt-out--73.7%

        \[\leadsto \frac{0.5 + \left(-\frac{\color{blue}{x \cdot \left(0.5 - 0.25\right)}}{s}\right)}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      3. metadata-eval73.7%

        \[\leadsto \frac{0.5 + \left(-\frac{x \cdot \color{blue}{0.25}}{s}\right)}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      4. *-commutative73.7%

        \[\leadsto \frac{0.5 + \left(-\frac{\color{blue}{0.25 \cdot x}}{s}\right)}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      5. associate-*r/73.7%

        \[\leadsto \frac{0.5 + \left(-\color{blue}{0.25 \cdot \frac{x}{s}}\right)}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      6. unsub-neg73.7%

        \[\leadsto \frac{\color{blue}{0.5 - 0.25 \cdot \frac{x}{s}}}{s + \frac{s}{e^{\frac{x}{s}}}} \]
      7. *-commutative73.7%

        \[\leadsto \frac{0.5 - \color{blue}{\frac{x}{s} \cdot 0.25}}{s + \frac{s}{e^{\frac{x}{s}}}} \]
    10. Simplified73.7%

      \[\leadsto \frac{\color{blue}{0.5 - \frac{x}{s} \cdot 0.25}}{s + \frac{s}{e^{\frac{x}{s}}}} \]
    11. Taylor expanded in x around 0 48.9%

      \[\leadsto \frac{0.5 - \frac{x}{s} \cdot 0.25}{\color{blue}{2 \cdot s + x \cdot \left(0.5 \cdot \frac{x}{s} - 1\right)}} \]

    if 1.00000003e-22 < x

    1. Initial program 100.0%

      \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
      2. fabs-neg100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
      4. fabs-neg100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
      5. distribute-lft-in99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
      6. *-rgt-identity99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
      7. +-commutative99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    6. Step-by-step derivation
      1. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
    7. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
    8. Taylor expanded in s around inf 98.1%

      \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \color{blue}{s}} \]
    9. Step-by-step derivation
      1. add-log-exp95.7%

        \[\leadsto \color{blue}{\log \left(e^{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + s}}\right)} \]
      2. div-inv95.7%

        \[\leadsto \log \left(e^{\color{blue}{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1} \cdot \frac{1}{s + s}}}\right) \]
      3. exp-prod95.7%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{s + s}\right)}\right)} \]
      4. flip-+92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\color{blue}{\frac{s \cdot s - s \cdot s}{s - s}}}\right)}\right) \]
      5. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{0}}{s - s}}\right)}\right) \]
      6. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{s - s}}{s - s}}\right)}\right) \]
      7. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{0}}}\right)}\right) \]
      8. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{s \cdot s - s \cdot s}}}\right)}\right) \]
      9. clear-num92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(\frac{s \cdot s - s \cdot s}{s - s}\right)}}\right) \]
      10. flip-+93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s + s\right)}}\right) \]
      11. add-sqr-sqrt93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s} \cdot \sqrt{s}}\right)}\right) \]
      12. sqrt-unprod93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s \cdot s}}\right)}\right) \]
      13. sqr-neg93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \sqrt{\color{blue}{\left(-s\right) \cdot \left(-s\right)}}\right)}\right) \]
      14. sqrt-unprod92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{-s} \cdot \sqrt{-s}}\right)}\right) \]
      15. add-sqr-sqrt92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\left(-s\right)}\right)}\right) \]
      16. sub-neg92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s - s\right)}}\right) \]
      17. +-inverses92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{0}}\right) \]
      18. metadata-eval92.6%

        \[\leadsto \log \color{blue}{1} \]
    10. Applied egg-rr92.6%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification66.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.000000031374395 \cdot 10^{-22}:\\ \;\;\;\;\frac{0.5 - \frac{x}{s} \cdot 0.25}{s \cdot 2 + x \cdot \left(\frac{x}{s} \cdot 0.5 + -1\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 85.7% accurate, 77.2× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 1.000000031374395 \cdot 10^{-22}:\\ \;\;\;\;\frac{0.25}{s}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s)
 :precision binary32
 (if (<= x_m 1.000000031374395e-22) (/ 0.25 s) 0.0))
x_m = fabs(x);
float code(float x_m, float s) {
	float tmp;
	if (x_m <= 1.000000031374395e-22f) {
		tmp = 0.25f / s;
	} else {
		tmp = 0.0f;
	}
	return tmp;
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    real(4) :: tmp
    if (x_m <= 1.000000031374395e-22) then
        tmp = 0.25e0 / s
    else
        tmp = 0.0e0
    end if
    code = tmp
end function
x_m = abs(x)
function code(x_m, s)
	tmp = Float32(0.0)
	if (x_m <= Float32(1.000000031374395e-22))
		tmp = Float32(Float32(0.25) / s);
	else
		tmp = Float32(0.0);
	end
	return tmp
end
x_m = abs(x);
function tmp_2 = code(x_m, s)
	tmp = single(0.0);
	if (x_m <= single(1.000000031374395e-22))
		tmp = single(0.25) / s;
	else
		tmp = single(0.0);
	end
	tmp_2 = tmp;
end
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 1.000000031374395 \cdot 10^{-22}:\\
\;\;\;\;\frac{0.25}{s}\\

\mathbf{else}:\\
\;\;\;\;0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.00000003e-22

    1. Initial program 99.7%

      \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. Step-by-step derivation
      1. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{-\color{blue}{\left|-x\right|}}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
      2. distribute-frac-neg99.7%

        \[\leadsto \frac{e^{\color{blue}{-\frac{\left|-x\right|}{s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
      3. distribute-frac-neg299.7%

        \[\leadsto \frac{e^{\color{blue}{\frac{\left|-x\right|}{-s}}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
      4. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{\color{blue}{\left|x\right|}}{-s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
      5. *-commutative99.7%

        \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
      6. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
      7. +-commutative99.7%

        \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
      8. fabs-neg99.7%

        \[\leadsto \frac{e^{\frac{\left|x\right|}{-s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{\frac{e^{\frac{\left|x\right|}{-s}}}{s \cdot \left(\left(1 + e^{\frac{\left|x\right|}{-s}}\right) \cdot \left(1 + e^{\frac{\left|x\right|}{-s}}\right)\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in s around inf 35.8%

      \[\leadsto \color{blue}{\frac{0.25}{s}} \]

    if 1.00000003e-22 < x

    1. Initial program 100.0%

      \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
    2. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
      2. fabs-neg100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
      4. fabs-neg100.0%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
      5. distribute-lft-in99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
      6. *-rgt-identity99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
      7. +-commutative99.9%

        \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 99.9%

      \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
    6. Step-by-step derivation
      1. associate-/r*99.9%

        \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
    7. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
    8. Taylor expanded in s around inf 98.1%

      \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \color{blue}{s}} \]
    9. Step-by-step derivation
      1. add-log-exp95.7%

        \[\leadsto \color{blue}{\log \left(e^{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + s}}\right)} \]
      2. div-inv95.7%

        \[\leadsto \log \left(e^{\color{blue}{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1} \cdot \frac{1}{s + s}}}\right) \]
      3. exp-prod95.7%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{s + s}\right)}\right)} \]
      4. flip-+92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\color{blue}{\frac{s \cdot s - s \cdot s}{s - s}}}\right)}\right) \]
      5. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{0}}{s - s}}\right)}\right) \]
      6. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{s - s}}{s - s}}\right)}\right) \]
      7. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{0}}}\right)}\right) \]
      8. +-inverses92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{s \cdot s - s \cdot s}}}\right)}\right) \]
      9. clear-num92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(\frac{s \cdot s - s \cdot s}{s - s}\right)}}\right) \]
      10. flip-+93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s + s\right)}}\right) \]
      11. add-sqr-sqrt93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s} \cdot \sqrt{s}}\right)}\right) \]
      12. sqrt-unprod93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s \cdot s}}\right)}\right) \]
      13. sqr-neg93.5%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \sqrt{\color{blue}{\left(-s\right) \cdot \left(-s\right)}}\right)}\right) \]
      14. sqrt-unprod92.2%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{-s} \cdot \sqrt{-s}}\right)}\right) \]
      15. add-sqr-sqrt92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\left(-s\right)}\right)}\right) \]
      16. sub-neg92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s - s\right)}}\right) \]
      17. +-inverses92.6%

        \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{0}}\right) \]
      18. metadata-eval92.6%

        \[\leadsto \log \color{blue}{1} \]
    10. Applied egg-rr92.6%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 74.3% accurate, 620.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ 0 \end{array} \]
x_m = (fabs.f32 x)
(FPCore (x_m s) :precision binary32 0.0)
x_m = fabs(x);
float code(float x_m, float s) {
	return 0.0f;
}
x_m = abs(x)
real(4) function code(x_m, s)
    real(4), intent (in) :: x_m
    real(4), intent (in) :: s
    code = 0.0e0
end function
x_m = abs(x)
function code(x_m, s)
	return Float32(0.0)
end
x_m = abs(x);
function tmp = code(x_m, s)
	tmp = single(0.0);
end
\begin{array}{l}
x_m = \left|x\right|

\\
0
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{e^{\frac{-\left|x\right|}{s}}}{\left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right) \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)} \]
  2. Step-by-step derivation
    1. *-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\color{blue}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)}} \]
    2. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\color{blue}{\left|-x\right|}}{s}}\right) \cdot \left(s \cdot \left(1 + e^{\frac{-\left|x\right|}{s}}\right)\right)} \]
    3. +-commutative99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \color{blue}{\left(e^{\frac{-\left|x\right|}{s}} + 1\right)}\right)} \]
    4. fabs-neg99.8%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot \left(e^{\frac{-\color{blue}{\left|-x\right|}}{s}} + 1\right)\right)} \]
    5. distribute-lft-in99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s \cdot e^{\frac{-\left|-x\right|}{s}} + s \cdot 1\right)}} \]
    6. *-rgt-identity99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \left(s \cdot e^{\frac{-\left|-x\right|}{s}} + \color{blue}{s}\right)} \]
    7. +-commutative99.9%

      \[\leadsto \frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|-x\right|}{s}}\right) \cdot \color{blue}{\left(s + s \cdot e^{\frac{-\left|-x\right|}{s}}\right)}} \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{\frac{e^{\frac{-\left|x\right|}{s}}}{\left(1 + e^{\frac{-\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 99.8%

    \[\leadsto \color{blue}{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{\left(1 + e^{-1 \cdot \frac{\left|x\right|}{s}}\right) \cdot \left(s + \frac{s}{e^{\frac{\left|x\right|}{s}}}\right)}} \]
  6. Step-by-step derivation
    1. associate-/r*99.8%

      \[\leadsto \color{blue}{\frac{\frac{e^{-1 \cdot \frac{\left|x\right|}{s}}}{1 + e^{-1 \cdot \frac{\left|x\right|}{s}}}}{s + \frac{s}{e^{\frac{\left|x\right|}{s}}}}} \]
  7. Simplified63.2%

    \[\leadsto \color{blue}{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \frac{s}{e^{\frac{x}{s}}}}} \]
  8. Taylor expanded in s around inf 59.1%

    \[\leadsto \frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + \color{blue}{s}} \]
  9. Step-by-step derivation
    1. add-log-exp42.8%

      \[\leadsto \color{blue}{\log \left(e^{\frac{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}{s + s}}\right)} \]
    2. div-inv42.8%

      \[\leadsto \log \left(e^{\color{blue}{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1} \cdot \frac{1}{s + s}}}\right) \]
    3. exp-prod42.8%

      \[\leadsto \log \color{blue}{\left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{s + s}\right)}\right)} \]
    4. flip-+38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\color{blue}{\frac{s \cdot s - s \cdot s}{s - s}}}\right)}\right) \]
    5. +-inverses38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{0}}{s - s}}\right)}\right) \]
    6. +-inverses38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{\color{blue}{s - s}}{s - s}}\right)}\right) \]
    7. +-inverses38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{0}}}\right)}\right) \]
    8. +-inverses38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(\frac{1}{\frac{s - s}{\color{blue}{s \cdot s - s \cdot s}}}\right)}\right) \]
    9. clear-num38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(\frac{s \cdot s - s \cdot s}{s - s}\right)}}\right) \]
    10. flip-+40.4%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s + s\right)}}\right) \]
    11. add-sqr-sqrt40.4%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s} \cdot \sqrt{s}}\right)}\right) \]
    12. sqrt-unprod40.4%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{s \cdot s}}\right)}\right) \]
    13. sqr-neg40.4%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \sqrt{\color{blue}{\left(-s\right) \cdot \left(-s\right)}}\right)}\right) \]
    14. sqrt-unprod38.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\sqrt{-s} \cdot \sqrt{-s}}\right)}\right) \]
    15. add-sqr-sqrt76.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\left(s + \color{blue}{\left(-s\right)}\right)}\right) \]
    16. sub-neg76.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{\left(s - s\right)}}\right) \]
    17. +-inverses76.3%

      \[\leadsto \log \left({\left(e^{\frac{e^{\frac{x}{-s}}}{e^{\frac{x}{-s}} + 1}}\right)}^{\color{blue}{0}}\right) \]
    18. metadata-eval76.3%

      \[\leadsto \log \color{blue}{1} \]
  10. Applied egg-rr76.3%

    \[\leadsto \color{blue}{0} \]
  11. Add Preprocessing

Reproduce

?
herbie shell --seed 2024139 
(FPCore (x s)
  :name "Logistic distribution"
  :precision binary32
  :pre (and (<= 0.0 s) (<= s 1.0651631))
  (/ (exp (/ (- (fabs x)) s)) (* (* s (+ 1.0 (exp (/ (- (fabs x)) s)))) (+ 1.0 (exp (/ (- (fabs x)) s))))))