VandenBroeck and Keller, Equation (20)

Percentage Accurate: 6.8% → 98.8%
Time: 16.8s
Alternatives: 11
Speedup: 33.2×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\pi}{4} \cdot f\\ t_1 := e^{t\_0}\\ t_2 := e^{-t\_0}\\ -\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right) \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (let* ((t_0 (* (/ PI 4.0) f)) (t_1 (exp t_0)) (t_2 (exp (- t_0))))
   (- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ t_1 t_2) (- t_1 t_2)))))))
double code(double f) {
	double t_0 = (((double) M_PI) / 4.0) * f;
	double t_1 = exp(t_0);
	double t_2 = exp(-t_0);
	return -((1.0 / (((double) M_PI) / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
}
public static double code(double f) {
	double t_0 = (Math.PI / 4.0) * f;
	double t_1 = Math.exp(t_0);
	double t_2 = Math.exp(-t_0);
	return -((1.0 / (Math.PI / 4.0)) * Math.log(((t_1 + t_2) / (t_1 - t_2))));
}
def code(f):
	t_0 = (math.pi / 4.0) * f
	t_1 = math.exp(t_0)
	t_2 = math.exp(-t_0)
	return -((1.0 / (math.pi / 4.0)) * math.log(((t_1 + t_2) / (t_1 - t_2))))
function code(f)
	t_0 = Float64(Float64(pi / 4.0) * f)
	t_1 = exp(t_0)
	t_2 = exp(Float64(-t_0))
	return Float64(-Float64(Float64(1.0 / Float64(pi / 4.0)) * log(Float64(Float64(t_1 + t_2) / Float64(t_1 - t_2)))))
end
function tmp = code(f)
	t_0 = (pi / 4.0) * f;
	t_1 = exp(t_0);
	t_2 = exp(-t_0);
	tmp = -((1.0 / (pi / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
end
code[f_] := Block[{t$95$0 = N[(N[(Pi / 4.0), $MachinePrecision] * f), $MachinePrecision]}, Block[{t$95$1 = N[Exp[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t$95$0)], $MachinePrecision]}, (-N[(N[(1.0 / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision] * N[Log[N[(N[(t$95$1 + t$95$2), $MachinePrecision] / N[(t$95$1 - t$95$2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision])]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\pi}{4} \cdot f\\
t_1 := e^{t\_0}\\
t_2 := e^{-t\_0}\\
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right)
\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 11 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: 6.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\pi}{4} \cdot f\\ t_1 := e^{t\_0}\\ t_2 := e^{-t\_0}\\ -\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right) \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (let* ((t_0 (* (/ PI 4.0) f)) (t_1 (exp t_0)) (t_2 (exp (- t_0))))
   (- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ t_1 t_2) (- t_1 t_2)))))))
double code(double f) {
	double t_0 = (((double) M_PI) / 4.0) * f;
	double t_1 = exp(t_0);
	double t_2 = exp(-t_0);
	return -((1.0 / (((double) M_PI) / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
}
public static double code(double f) {
	double t_0 = (Math.PI / 4.0) * f;
	double t_1 = Math.exp(t_0);
	double t_2 = Math.exp(-t_0);
	return -((1.0 / (Math.PI / 4.0)) * Math.log(((t_1 + t_2) / (t_1 - t_2))));
}
def code(f):
	t_0 = (math.pi / 4.0) * f
	t_1 = math.exp(t_0)
	t_2 = math.exp(-t_0)
	return -((1.0 / (math.pi / 4.0)) * math.log(((t_1 + t_2) / (t_1 - t_2))))
function code(f)
	t_0 = Float64(Float64(pi / 4.0) * f)
	t_1 = exp(t_0)
	t_2 = exp(Float64(-t_0))
	return Float64(-Float64(Float64(1.0 / Float64(pi / 4.0)) * log(Float64(Float64(t_1 + t_2) / Float64(t_1 - t_2)))))
end
function tmp = code(f)
	t_0 = (pi / 4.0) * f;
	t_1 = exp(t_0);
	t_2 = exp(-t_0);
	tmp = -((1.0 / (pi / 4.0)) * log(((t_1 + t_2) / (t_1 - t_2))));
end
code[f_] := Block[{t$95$0 = N[(N[(Pi / 4.0), $MachinePrecision] * f), $MachinePrecision]}, Block[{t$95$1 = N[Exp[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t$95$0)], $MachinePrecision]}, (-N[(N[(1.0 / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision] * N[Log[N[(N[(t$95$1 + t$95$2), $MachinePrecision] / N[(t$95$1 - t$95$2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision])]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\pi}{4} \cdot f\\
t_1 := e^{t\_0}\\
t_2 := e^{-t\_0}\\
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{t\_1 + t\_2}{t\_1 - t\_2}\right)
\end{array}
\end{array}

Alternative 1: 98.8% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)}\right) \cdot \frac{-4}{\pi} \end{array} \]
(FPCore (f)
 :precision binary64
 (*
  (log (+ (/ -1.0 (expm1 (* (* -0.5 PI) f))) (/ 1.0 (expm1 (* f (* PI 0.5))))))
  (/ -4.0 PI)))
double code(double f) {
	return log(((-1.0 / expm1(((-0.5 * ((double) M_PI)) * f))) + (1.0 / expm1((f * (((double) M_PI) * 0.5)))))) * (-4.0 / ((double) M_PI));
}
public static double code(double f) {
	return Math.log(((-1.0 / Math.expm1(((-0.5 * Math.PI) * f))) + (1.0 / Math.expm1((f * (Math.PI * 0.5)))))) * (-4.0 / Math.PI);
}
def code(f):
	return math.log(((-1.0 / math.expm1(((-0.5 * math.pi) * f))) + (1.0 / math.expm1((f * (math.pi * 0.5)))))) * (-4.0 / math.pi)
function code(f)
	return Float64(log(Float64(Float64(-1.0 / expm1(Float64(Float64(-0.5 * pi) * f))) + Float64(1.0 / expm1(Float64(f * Float64(pi * 0.5)))))) * Float64(-4.0 / pi))
end
code[f_] := N[(N[Log[N[(N[(-1.0 / N[(Exp[N[(N[(-0.5 * Pi), $MachinePrecision] * f), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision] + N[(1.0 / N[(Exp[N[(f * N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(-4.0 / Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)}\right) \cdot \frac{-4}{\pi}
\end{array}
Derivation
  1. Initial program 6.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Simplified99.3%

    \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
  3. Add Preprocessing
  4. Final simplification99.3%

    \[\leadsto \log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)}\right) \cdot \frac{-4}{\pi} \]
  5. Add Preprocessing

Alternative 2: 98.3% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 220:\\ \;\;\;\;-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi} - {f}^{2} \cdot \left(\pi \cdot 0.08333333333333333\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 220.0)
   (-
    (* -4.0 (/ (- (log (/ 4.0 PI)) (log f)) PI))
    (* (pow f 2.0) (* PI 0.08333333333333333)))
   0.0))
double code(double f) {
	double tmp;
	if (f <= 220.0) {
		tmp = (-4.0 * ((log((4.0 / ((double) M_PI))) - log(f)) / ((double) M_PI))) - (pow(f, 2.0) * (((double) M_PI) * 0.08333333333333333));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 220.0) {
		tmp = (-4.0 * ((Math.log((4.0 / Math.PI)) - Math.log(f)) / Math.PI)) - (Math.pow(f, 2.0) * (Math.PI * 0.08333333333333333));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 220.0:
		tmp = (-4.0 * ((math.log((4.0 / math.pi)) - math.log(f)) / math.pi)) - (math.pow(f, 2.0) * (math.pi * 0.08333333333333333))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 220.0)
		tmp = Float64(Float64(-4.0 * Float64(Float64(log(Float64(4.0 / pi)) - log(f)) / pi)) - Float64((f ^ 2.0) * Float64(pi * 0.08333333333333333)));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 220.0)
		tmp = (-4.0 * ((log((4.0 / pi)) - log(f)) / pi)) - ((f ^ 2.0) * (pi * 0.08333333333333333));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 220.0], N[(N[(-4.0 * N[(N[(N[Log[N[(4.0 / Pi), $MachinePrecision]], $MachinePrecision] - N[Log[f], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision]), $MachinePrecision] - N[(N[Power[f, 2.0], $MachinePrecision] * N[(Pi * 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 220:\\
\;\;\;\;-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi} - {f}^{2} \cdot \left(\pi \cdot 0.08333333333333333\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 220

    1. Initial program 6.4%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Taylor expanded in f around 0 98.7%

      \[\leadsto \color{blue}{-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}{\pi} + -1 \cdot \left({f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)\right)} \]
    5. Step-by-step derivation
      1. mul-1-neg98.7%

        \[\leadsto -4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}{\pi} + \color{blue}{\left(-{f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)\right)} \]
      2. unsub-neg98.7%

        \[\leadsto \color{blue}{-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}{\pi} - {f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)} \]
      3. mul-1-neg98.7%

        \[\leadsto -4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + \color{blue}{\left(-\log f\right)}}{\pi} - {f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right) \]
      4. unsub-neg98.7%

        \[\leadsto -4 \cdot \frac{\color{blue}{\log \left(\frac{4}{\pi}\right) - \log f}}{\pi} - {f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right) \]
      5. distribute-rgt-out98.7%

        \[\leadsto -4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi} - {f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \color{blue}{\pi \cdot \left(-0.125 + 0.08333333333333333\right)}\right) \]
      6. metadata-eval98.7%

        \[\leadsto -4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi} - {f}^{2} \cdot \left(\left(-0.08333333333333333 \cdot \pi + 0.125 \cdot \pi\right) - \pi \cdot \color{blue}{-0.041666666666666664}\right) \]
    6. Simplified98.7%

      \[\leadsto \color{blue}{-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi} - {f}^{2} \cdot \left(\pi \cdot 0.08333333333333333\right)} \]

    if 220 < f

    1. Initial program 0.0%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr3.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses100.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/100.0%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod100.0%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval100.0%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval100.0%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr100.0%

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

Alternative 3: 98.2% accurate, 2.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)} + \frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot 0.041666666666666664\right)\right) + \frac{2}{\pi}}{f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 230.0)
   (*
    (/ -4.0 PI)
    (log
     (+
      (/ 1.0 (expm1 (* f (* PI 0.5))))
      (/ (+ (* f (+ 0.5 (* f (* PI 0.041666666666666664)))) (/ 2.0 PI)) f))))
   0.0))
double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = (-4.0 / ((double) M_PI)) * log(((1.0 / expm1((f * (((double) M_PI) * 0.5)))) + (((f * (0.5 + (f * (((double) M_PI) * 0.041666666666666664)))) + (2.0 / ((double) M_PI))) / f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = (-4.0 / Math.PI) * Math.log(((1.0 / Math.expm1((f * (Math.PI * 0.5)))) + (((f * (0.5 + (f * (Math.PI * 0.041666666666666664)))) + (2.0 / Math.PI)) / f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 230.0:
		tmp = (-4.0 / math.pi) * math.log(((1.0 / math.expm1((f * (math.pi * 0.5)))) + (((f * (0.5 + (f * (math.pi * 0.041666666666666664)))) + (2.0 / math.pi)) / f)))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 230.0)
		tmp = Float64(Float64(-4.0 / pi) * log(Float64(Float64(1.0 / expm1(Float64(f * Float64(pi * 0.5)))) + Float64(Float64(Float64(f * Float64(0.5 + Float64(f * Float64(pi * 0.041666666666666664)))) + Float64(2.0 / pi)) / f))));
	else
		tmp = 0.0;
	end
	return tmp
end
code[f_] := If[LessEqual[f, 230.0], N[(N[(-4.0 / Pi), $MachinePrecision] * N[Log[N[(N[(1.0 / N[(Exp[N[(f * N[(Pi * 0.5), $MachinePrecision]), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(f * N[(0.5 + N[(f * N[(Pi * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(2.0 / Pi), $MachinePrecision]), $MachinePrecision] / f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 230:\\
\;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)} + \frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot 0.041666666666666664\right)\right) + \frac{2}{\pi}}{f}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 230

    1. Initial program 6.4%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Taylor expanded in f around 0 98.6%

      \[\leadsto \log \left(\color{blue}{\frac{f \cdot \left(0.5 + -1 \cdot \left(f \cdot \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)\right) + 2 \cdot \frac{1}{\pi}}{f}} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    5. Step-by-step derivation
      1. pow198.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + \color{blue}{{\left(-1 \cdot \left(f \cdot \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)\right)}^{1}}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      2. mul-1-neg98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + {\color{blue}{\left(-f \cdot \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)}}^{1}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      3. distribute-rgt-out98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + {\left(-f \cdot \color{blue}{\left(\pi \cdot \left(-0.125 + 0.08333333333333333\right)\right)}\right)}^{1}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      4. metadata-eval98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + {\left(-f \cdot \left(\pi \cdot \color{blue}{-0.041666666666666664}\right)\right)}^{1}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    6. Applied egg-rr98.6%

      \[\leadsto \log \left(\frac{f \cdot \left(0.5 + \color{blue}{{\left(-f \cdot \left(\pi \cdot -0.041666666666666664\right)\right)}^{1}}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    7. Step-by-step derivation
      1. unpow198.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + \color{blue}{\left(-f \cdot \left(\pi \cdot -0.041666666666666664\right)\right)}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      2. distribute-rgt-neg-in98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + \color{blue}{f \cdot \left(-\pi \cdot -0.041666666666666664\right)}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      3. distribute-rgt-neg-in98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + f \cdot \color{blue}{\left(\pi \cdot \left(--0.041666666666666664\right)\right)}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
      4. metadata-eval98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot \color{blue}{0.041666666666666664}\right)\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    8. Simplified98.6%

      \[\leadsto \log \left(\frac{f \cdot \left(0.5 + \color{blue}{f \cdot \left(\pi \cdot 0.041666666666666664\right)}\right) + 2 \cdot \frac{1}{\pi}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    9. Step-by-step derivation
      1. un-div-inv98.6%

        \[\leadsto \log \left(\frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot 0.041666666666666664\right)\right) + \color{blue}{\frac{2}{\pi}}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]
    10. Applied egg-rr98.6%

      \[\leadsto \log \left(\frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot 0.041666666666666664\right)\right) + \color{blue}{\frac{2}{\pi}}}{f} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi} \]

    if 230 < f

    1. Initial program 0.0%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr3.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses100.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/100.0%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod100.0%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval100.0%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval100.0%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{1}{\mathsf{expm1}\left(f \cdot \left(\pi \cdot 0.5\right)\right)} + \frac{f \cdot \left(0.5 + f \cdot \left(\pi \cdot 0.041666666666666664\right)\right) + \frac{2}{\pi}}{f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 97.8% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 1.26) (* -4.0 (/ (- (log (/ 4.0 PI)) (log f)) PI)) 0.0))
double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = -4.0 * ((log((4.0 / ((double) M_PI))) - log(f)) / ((double) M_PI));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = -4.0 * ((Math.log((4.0 / Math.PI)) - Math.log(f)) / Math.PI);
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 1.26:
		tmp = -4.0 * ((math.log((4.0 / math.pi)) - math.log(f)) / math.pi)
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 1.26)
		tmp = Float64(-4.0 * Float64(Float64(log(Float64(4.0 / pi)) - log(f)) / pi));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 1.26)
		tmp = -4.0 * ((log((4.0 / pi)) - log(f)) / pi);
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 1.26], N[(-4.0 * N[(N[(N[Log[N[(4.0 / Pi), $MachinePrecision]], $MachinePrecision] - N[Log[f], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 1.26:\\
\;\;\;\;-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 1.26000000000000001

    1. Initial program 6.1%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.4%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Taylor expanded in f around 0 98.7%

      \[\leadsto \color{blue}{-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}{\pi}} \]
    5. Step-by-step derivation
      1. mul-1-neg98.7%

        \[\leadsto -4 \cdot \frac{\log \left(\frac{4}{\pi}\right) + \color{blue}{\left(-\log f\right)}}{\pi} \]
      2. unsub-neg98.7%

        \[\leadsto -4 \cdot \frac{\color{blue}{\log \left(\frac{4}{\pi}\right) - \log f}}{\pi} \]
    6. Simplified98.7%

      \[\leadsto \color{blue}{-4 \cdot \frac{\log \left(\frac{4}{\pi}\right) - \log f}{\pi}} \]

    if 1.26000000000000001 < f

    1. Initial program 12.3%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified95.7%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr4.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses83.9%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified83.9%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp83.9%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval83.9%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/83.9%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod83.9%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval83.9%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval83.9%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr83.9%

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

Alternative 5: 97.7% accurate, 3.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 2 \cdot \frac{-1}{\pi}\\ \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{-0.5 \cdot f - t\_0}{f} - \frac{f \cdot \left(f \cdot \left(\pi \cdot 0.08333333333333333 + \pi \cdot -0.125\right) - 0.5\right) + t\_0}{f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (let* ((t_0 (* 2.0 (/ -1.0 PI))))
   (if (<= f 230.0)
     (*
      (/ -4.0 PI)
      (log
       (-
        (/ (- (* -0.5 f) t_0) f)
        (/
         (+
          (* f (- (* f (+ (* PI 0.08333333333333333) (* PI -0.125))) 0.5))
          t_0)
         f))))
     0.0)))
double code(double f) {
	double t_0 = 2.0 * (-1.0 / ((double) M_PI));
	double tmp;
	if (f <= 230.0) {
		tmp = (-4.0 / ((double) M_PI)) * log(((((-0.5 * f) - t_0) / f) - (((f * ((f * ((((double) M_PI) * 0.08333333333333333) + (((double) M_PI) * -0.125))) - 0.5)) + t_0) / f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double t_0 = 2.0 * (-1.0 / Math.PI);
	double tmp;
	if (f <= 230.0) {
		tmp = (-4.0 / Math.PI) * Math.log(((((-0.5 * f) - t_0) / f) - (((f * ((f * ((Math.PI * 0.08333333333333333) + (Math.PI * -0.125))) - 0.5)) + t_0) / f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	t_0 = 2.0 * (-1.0 / math.pi)
	tmp = 0
	if f <= 230.0:
		tmp = (-4.0 / math.pi) * math.log(((((-0.5 * f) - t_0) / f) - (((f * ((f * ((math.pi * 0.08333333333333333) + (math.pi * -0.125))) - 0.5)) + t_0) / f)))
	else:
		tmp = 0.0
	return tmp
function code(f)
	t_0 = Float64(2.0 * Float64(-1.0 / pi))
	tmp = 0.0
	if (f <= 230.0)
		tmp = Float64(Float64(-4.0 / pi) * log(Float64(Float64(Float64(Float64(-0.5 * f) - t_0) / f) - Float64(Float64(Float64(f * Float64(Float64(f * Float64(Float64(pi * 0.08333333333333333) + Float64(pi * -0.125))) - 0.5)) + t_0) / f))));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	t_0 = 2.0 * (-1.0 / pi);
	tmp = 0.0;
	if (f <= 230.0)
		tmp = (-4.0 / pi) * log(((((-0.5 * f) - t_0) / f) - (((f * ((f * ((pi * 0.08333333333333333) + (pi * -0.125))) - 0.5)) + t_0) / f)));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := Block[{t$95$0 = N[(2.0 * N[(-1.0 / Pi), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[f, 230.0], N[(N[(-4.0 / Pi), $MachinePrecision] * N[Log[N[(N[(N[(N[(-0.5 * f), $MachinePrecision] - t$95$0), $MachinePrecision] / f), $MachinePrecision] - N[(N[(N[(f * N[(N[(f * N[(N[(Pi * 0.08333333333333333), $MachinePrecision] + N[(Pi * -0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision] / f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 0.0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 2 \cdot \frac{-1}{\pi}\\
\mathbf{if}\;f \leq 230:\\
\;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{-0.5 \cdot f - t\_0}{f} - \frac{f \cdot \left(f \cdot \left(\pi \cdot 0.08333333333333333 + \pi \cdot -0.125\right) - 0.5\right) + t\_0}{f}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 230

    1. Initial program 6.4%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Taylor expanded in f around 0 98.2%

      \[\leadsto \log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \color{blue}{\frac{-0.5 \cdot f + 2 \cdot \frac{1}{\pi}}{f}}\right) \cdot \frac{-4}{\pi} \]
    5. Taylor expanded in f around 0 98.3%

      \[\leadsto \log \left(\color{blue}{\frac{f \cdot \left(0.5 + -1 \cdot \left(f \cdot \left(-0.125 \cdot \pi + 0.08333333333333333 \cdot \pi\right)\right)\right) + 2 \cdot \frac{1}{\pi}}{f}} + \frac{-0.5 \cdot f + 2 \cdot \frac{1}{\pi}}{f}\right) \cdot \frac{-4}{\pi} \]

    if 230 < f

    1. Initial program 0.0%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr3.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses100.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/100.0%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod100.0%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval100.0%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval100.0%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{-0.5 \cdot f - 2 \cdot \frac{-1}{\pi}}{f} - \frac{f \cdot \left(f \cdot \left(\pi \cdot 0.08333333333333333 + \pi \cdot -0.125\right) - 0.5\right) + 2 \cdot \frac{-1}{\pi}}{f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 97.7% accurate, 4.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{-1}{\frac{-1}{\frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\pi \cdot -0.25}}}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 1.26)
   (/ -1.0 (/ -1.0 (/ (log (/ 4.0 (* PI f))) (* PI -0.25))))
   0.0))
double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = -1.0 / (-1.0 / (log((4.0 / (((double) M_PI) * f))) / (((double) M_PI) * -0.25)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = -1.0 / (-1.0 / (Math.log((4.0 / (Math.PI * f))) / (Math.PI * -0.25)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 1.26:
		tmp = -1.0 / (-1.0 / (math.log((4.0 / (math.pi * f))) / (math.pi * -0.25)))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 1.26)
		tmp = Float64(-1.0 / Float64(-1.0 / Float64(log(Float64(4.0 / Float64(pi * f))) / Float64(pi * -0.25))));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 1.26)
		tmp = -1.0 / (-1.0 / (log((4.0 / (pi * f))) / (pi * -0.25)));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 1.26], N[(-1.0 / N[(-1.0 / N[(N[Log[N[(4.0 / N[(Pi * f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[(Pi * -0.25), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 1.26:\\
\;\;\;\;\frac{-1}{\frac{-1}{\frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\pi \cdot -0.25}}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 1.26000000000000001

    1. Initial program 6.1%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.4%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr97.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Taylor expanded in f around 0 98.6%

      \[\leadsto \frac{1}{\color{blue}{-0.25 \cdot \frac{\pi}{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}}} \]
    6. Step-by-step derivation
      1. associate-*r/98.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}}} \]
      2. neg-mul-198.6%

        \[\leadsto \frac{1}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) + \color{blue}{\left(-\log f\right)}}} \]
      3. unsub-neg98.6%

        \[\leadsto \frac{1}{\frac{-0.25 \cdot \pi}{\color{blue}{\log \left(\frac{4}{\pi}\right) - \log f}}} \]
    7. Simplified98.6%

      \[\leadsto \frac{1}{\color{blue}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) - \log f}}} \]
    8. Step-by-step derivation
      1. clear-num98.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\log \left(\frac{4}{\pi}\right) - \log f}{-0.25 \cdot \pi}}}} \]
      2. inv-pow98.6%

        \[\leadsto \frac{1}{\color{blue}{{\left(\frac{\log \left(\frac{4}{\pi}\right) - \log f}{-0.25 \cdot \pi}\right)}^{-1}}} \]
      3. diff-log98.7%

        \[\leadsto \frac{1}{{\left(\frac{\color{blue}{\log \left(\frac{\frac{4}{\pi}}{f}\right)}}{-0.25 \cdot \pi}\right)}^{-1}} \]
      4. *-commutative98.7%

        \[\leadsto \frac{1}{{\left(\frac{\log \left(\frac{\frac{4}{\pi}}{f}\right)}{\color{blue}{\pi \cdot -0.25}}\right)}^{-1}} \]
    9. Applied egg-rr98.7%

      \[\leadsto \frac{1}{\color{blue}{{\left(\frac{\log \left(\frac{\frac{4}{\pi}}{f}\right)}{\pi \cdot -0.25}\right)}^{-1}}} \]
    10. Step-by-step derivation
      1. unpow-198.7%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\log \left(\frac{\frac{4}{\pi}}{f}\right)}{\pi \cdot -0.25}}}} \]
      2. associate-/l/98.7%

        \[\leadsto \frac{1}{\frac{1}{\frac{\log \color{blue}{\left(\frac{4}{f \cdot \pi}\right)}}{\pi \cdot -0.25}}} \]
    11. Simplified98.7%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{\log \left(\frac{4}{f \cdot \pi}\right)}{\pi \cdot -0.25}}}} \]

    if 1.26000000000000001 < f

    1. Initial program 12.3%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified95.7%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr4.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses83.9%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified83.9%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp83.9%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval83.9%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/83.9%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod83.9%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval83.9%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval83.9%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr83.9%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{-1}{\frac{-1}{\frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\pi \cdot -0.25}}}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 97.7% accurate, 4.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{1}{\frac{\pi \cdot -0.25}{\log \left(\frac{4}{\pi \cdot f}\right)}}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 1.26) (/ 1.0 (/ (* PI -0.25) (log (/ 4.0 (* PI f))))) 0.0))
double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = 1.0 / ((((double) M_PI) * -0.25) / log((4.0 / (((double) M_PI) * f))));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = 1.0 / ((Math.PI * -0.25) / Math.log((4.0 / (Math.PI * f))));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 1.26:
		tmp = 1.0 / ((math.pi * -0.25) / math.log((4.0 / (math.pi * f))))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 1.26)
		tmp = Float64(1.0 / Float64(Float64(pi * -0.25) / log(Float64(4.0 / Float64(pi * f)))));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 1.26)
		tmp = 1.0 / ((pi * -0.25) / log((4.0 / (pi * f))));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 1.26], N[(1.0 / N[(N[(Pi * -0.25), $MachinePrecision] / N[Log[N[(4.0 / N[(Pi * f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 1.26:\\
\;\;\;\;\frac{1}{\frac{\pi \cdot -0.25}{\log \left(\frac{4}{\pi \cdot f}\right)}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 1.26000000000000001

    1. Initial program 6.1%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.4%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr97.8%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Taylor expanded in f around 0 98.6%

      \[\leadsto \frac{1}{\color{blue}{-0.25 \cdot \frac{\pi}{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}}} \]
    6. Step-by-step derivation
      1. associate-*r/98.6%

        \[\leadsto \frac{1}{\color{blue}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) + -1 \cdot \log f}}} \]
      2. neg-mul-198.6%

        \[\leadsto \frac{1}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) + \color{blue}{\left(-\log f\right)}}} \]
      3. unsub-neg98.6%

        \[\leadsto \frac{1}{\frac{-0.25 \cdot \pi}{\color{blue}{\log \left(\frac{4}{\pi}\right) - \log f}}} \]
    7. Simplified98.6%

      \[\leadsto \frac{1}{\color{blue}{\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) - \log f}}} \]
    8. Step-by-step derivation
      1. inv-pow98.6%

        \[\leadsto \color{blue}{{\left(\frac{-0.25 \cdot \pi}{\log \left(\frac{4}{\pi}\right) - \log f}\right)}^{-1}} \]
      2. *-commutative98.6%

        \[\leadsto {\left(\frac{\color{blue}{\pi \cdot -0.25}}{\log \left(\frac{4}{\pi}\right) - \log f}\right)}^{-1} \]
      3. diff-log98.6%

        \[\leadsto {\left(\frac{\pi \cdot -0.25}{\color{blue}{\log \left(\frac{\frac{4}{\pi}}{f}\right)}}\right)}^{-1} \]
    9. Applied egg-rr98.6%

      \[\leadsto \color{blue}{{\left(\frac{\pi \cdot -0.25}{\log \left(\frac{\frac{4}{\pi}}{f}\right)}\right)}^{-1}} \]
    10. Step-by-step derivation
      1. unpow-198.6%

        \[\leadsto \color{blue}{\frac{1}{\frac{\pi \cdot -0.25}{\log \left(\frac{\frac{4}{\pi}}{f}\right)}}} \]
      2. associate-/l/98.6%

        \[\leadsto \frac{1}{\frac{\pi \cdot -0.25}{\log \color{blue}{\left(\frac{4}{f \cdot \pi}\right)}}} \]
    11. Simplified98.6%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi \cdot -0.25}{\log \left(\frac{4}{f \cdot \pi}\right)}}} \]

    if 1.26000000000000001 < f

    1. Initial program 12.3%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified95.7%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr4.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses83.9%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified83.9%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp83.9%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval83.9%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/83.9%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod83.9%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval83.9%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval83.9%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr83.9%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{1}{\frac{\pi \cdot -0.25}{\log \left(\frac{4}{\pi \cdot f}\right)}}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 97.6% accurate, 4.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{4}{\pi \cdot f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 1.26) (* (/ -4.0 PI) (log (/ 4.0 (* PI f)))) 0.0))
double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = (-4.0 / ((double) M_PI)) * log((4.0 / (((double) M_PI) * f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 1.26) {
		tmp = (-4.0 / Math.PI) * Math.log((4.0 / (Math.PI * f)));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 1.26:
		tmp = (-4.0 / math.pi) * math.log((4.0 / (math.pi * f)))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 1.26)
		tmp = Float64(Float64(-4.0 / pi) * log(Float64(4.0 / Float64(pi * f))));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 1.26)
		tmp = (-4.0 / pi) * log((4.0 / (pi * f)));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 1.26], N[(N[(-4.0 / Pi), $MachinePrecision] * N[Log[N[(4.0 / N[(Pi * f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 1.26:\\
\;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{4}{\pi \cdot f}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 1.26000000000000001

    1. Initial program 6.1%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.4%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Taylor expanded in f around 0 98.6%

      \[\leadsto \log \color{blue}{\left(\frac{4}{f \cdot \pi}\right)} \cdot \frac{-4}{\pi} \]
    5. Step-by-step derivation
      1. *-commutative98.6%

        \[\leadsto \log \left(\frac{4}{\color{blue}{\pi \cdot f}}\right) \cdot \frac{-4}{\pi} \]
    6. Simplified98.6%

      \[\leadsto \log \color{blue}{\left(\frac{4}{\pi \cdot f}\right)} \cdot \frac{-4}{\pi} \]

    if 1.26000000000000001 < f

    1. Initial program 12.3%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified95.7%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr4.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses83.9%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified83.9%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp83.9%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval83.9%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/83.9%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod83.9%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval83.9%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval83.9%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr83.9%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 1.26:\\ \;\;\;\;\frac{-4}{\pi} \cdot \log \left(\frac{4}{\pi \cdot f}\right)\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 16.0% accurate, 26.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-1}{\frac{\pi}{-4} \cdot \left(f \cdot \left(\pi \cdot -0.25 - \frac{0.5}{f}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 230.0)
   (/ -1.0 (* (/ PI -4.0) (* f (- (* PI -0.25) (/ 0.5 f)))))
   0.0))
double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = -1.0 / ((((double) M_PI) / -4.0) * (f * ((((double) M_PI) * -0.25) - (0.5 / f))));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = -1.0 / ((Math.PI / -4.0) * (f * ((Math.PI * -0.25) - (0.5 / f))));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 230.0:
		tmp = -1.0 / ((math.pi / -4.0) * (f * ((math.pi * -0.25) - (0.5 / f))))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 230.0)
		tmp = Float64(-1.0 / Float64(Float64(pi / -4.0) * Float64(f * Float64(Float64(pi * -0.25) - Float64(0.5 / f)))));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 230.0)
		tmp = -1.0 / ((pi / -4.0) * (f * ((pi * -0.25) - (0.5 / f))));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 230.0], N[(-1.0 / N[(N[(Pi / -4.0), $MachinePrecision] * N[(f * N[(N[(Pi * -0.25), $MachinePrecision] - N[(0.5 / f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 230:\\
\;\;\;\;\frac{-1}{\frac{\pi}{-4} \cdot \left(f \cdot \left(\pi \cdot -0.25 - \frac{0.5}{f}\right)\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 230

    1. Initial program 6.4%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr97.5%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. *-un-lft-identity97.5%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot \pi}}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}} \]
      2. times-frac97.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)} \cdot \frac{\pi}{-4}}} \]
      3. count-297.4%

        \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)}} \cdot \frac{\pi}{-4}} \]
      4. *-commutative97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \color{blue}{\left(f \cdot -0.5\right)}\right)}\right)} \cdot \frac{\pi}{-4}} \]
    6. Applied egg-rr97.4%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{\log \left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)} \cdot \frac{\pi}{-4}}} \]
    7. Taylor expanded in f around 0 97.4%

      \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(\frac{f + 4 \cdot \frac{1}{\pi}}{f}\right)}} \cdot \frac{\pi}{-4}} \]
    8. Step-by-step derivation
      1. associate-*r/97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(\frac{f + \color{blue}{\frac{4 \cdot 1}{\pi}}}{f}\right)} \cdot \frac{\pi}{-4}} \]
      2. metadata-eval97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(\frac{f + \frac{\color{blue}{4}}{\pi}}{f}\right)} \cdot \frac{\pi}{-4}} \]
    9. Simplified97.4%

      \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(\frac{f + \frac{4}{\pi}}{f}\right)}} \cdot \frac{\pi}{-4}} \]
    10. Taylor expanded in f around -inf 14.4%

      \[\leadsto \frac{1}{\color{blue}{\left(-1 \cdot \left(f \cdot \left(-0.25 \cdot \pi - 0.5 \cdot \frac{1}{f}\right)\right)\right)} \cdot \frac{\pi}{-4}} \]
    11. Step-by-step derivation
      1. associate-*r*14.4%

        \[\leadsto \frac{1}{\color{blue}{\left(\left(-1 \cdot f\right) \cdot \left(-0.25 \cdot \pi - 0.5 \cdot \frac{1}{f}\right)\right)} \cdot \frac{\pi}{-4}} \]
      2. neg-mul-114.4%

        \[\leadsto \frac{1}{\left(\color{blue}{\left(-f\right)} \cdot \left(-0.25 \cdot \pi - 0.5 \cdot \frac{1}{f}\right)\right) \cdot \frac{\pi}{-4}} \]
      3. *-commutative14.4%

        \[\leadsto \frac{1}{\left(\left(-f\right) \cdot \left(\color{blue}{\pi \cdot -0.25} - 0.5 \cdot \frac{1}{f}\right)\right) \cdot \frac{\pi}{-4}} \]
      4. associate-*r/14.4%

        \[\leadsto \frac{1}{\left(\left(-f\right) \cdot \left(\pi \cdot -0.25 - \color{blue}{\frac{0.5 \cdot 1}{f}}\right)\right) \cdot \frac{\pi}{-4}} \]
      5. metadata-eval14.4%

        \[\leadsto \frac{1}{\left(\left(-f\right) \cdot \left(\pi \cdot -0.25 - \frac{\color{blue}{0.5}}{f}\right)\right) \cdot \frac{\pi}{-4}} \]
    12. Simplified14.4%

      \[\leadsto \frac{1}{\color{blue}{\left(\left(-f\right) \cdot \left(\pi \cdot -0.25 - \frac{0.5}{f}\right)\right)} \cdot \frac{\pi}{-4}} \]

    if 230 < f

    1. Initial program 0.0%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr3.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses100.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/100.0%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod100.0%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval100.0%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval100.0%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification16.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{-1}{\frac{\pi}{-4} \cdot \left(f \cdot \left(\pi \cdot -0.25 - \frac{0.5}{f}\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 10: 7.3% accurate, 33.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{1}{\frac{\pi}{-4} \cdot \left(\left(\pi \cdot f\right) \cdot 0.25\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \end{array} \]
(FPCore (f)
 :precision binary64
 (if (<= f 230.0) (/ 1.0 (* (/ PI -4.0) (* (* PI f) 0.25))) 0.0))
double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = 1.0 / ((((double) M_PI) / -4.0) * ((((double) M_PI) * f) * 0.25));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
public static double code(double f) {
	double tmp;
	if (f <= 230.0) {
		tmp = 1.0 / ((Math.PI / -4.0) * ((Math.PI * f) * 0.25));
	} else {
		tmp = 0.0;
	}
	return tmp;
}
def code(f):
	tmp = 0
	if f <= 230.0:
		tmp = 1.0 / ((math.pi / -4.0) * ((math.pi * f) * 0.25))
	else:
		tmp = 0.0
	return tmp
function code(f)
	tmp = 0.0
	if (f <= 230.0)
		tmp = Float64(1.0 / Float64(Float64(pi / -4.0) * Float64(Float64(pi * f) * 0.25)));
	else
		tmp = 0.0;
	end
	return tmp
end
function tmp_2 = code(f)
	tmp = 0.0;
	if (f <= 230.0)
		tmp = 1.0 / ((pi / -4.0) * ((pi * f) * 0.25));
	else
		tmp = 0.0;
	end
	tmp_2 = tmp;
end
code[f_] := If[LessEqual[f, 230.0], N[(1.0 / N[(N[(Pi / -4.0), $MachinePrecision] * N[(N[(Pi * f), $MachinePrecision] * 0.25), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;f \leq 230:\\
\;\;\;\;\frac{1}{\frac{\pi}{-4} \cdot \left(\left(\pi \cdot f\right) \cdot 0.25\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if f < 230

    1. Initial program 6.4%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr97.5%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. *-un-lft-identity97.5%

        \[\leadsto \frac{1}{\frac{\color{blue}{1 \cdot \pi}}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}} \]
      2. times-frac97.4%

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)} \cdot \frac{\pi}{-4}}} \]
      3. count-297.4%

        \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)}} \cdot \frac{\pi}{-4}} \]
      4. *-commutative97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \color{blue}{\left(f \cdot -0.5\right)}\right)}\right)} \cdot \frac{\pi}{-4}} \]
    6. Applied egg-rr97.4%

      \[\leadsto \frac{1}{\color{blue}{\frac{1}{\log \left(2 \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)} \cdot \frac{\pi}{-4}}} \]
    7. Taylor expanded in f around 0 97.4%

      \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(\frac{f + 4 \cdot \frac{1}{\pi}}{f}\right)}} \cdot \frac{\pi}{-4}} \]
    8. Step-by-step derivation
      1. associate-*r/97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(\frac{f + \color{blue}{\frac{4 \cdot 1}{\pi}}}{f}\right)} \cdot \frac{\pi}{-4}} \]
      2. metadata-eval97.4%

        \[\leadsto \frac{1}{\frac{1}{\log \left(\frac{f + \frac{\color{blue}{4}}{\pi}}{f}\right)} \cdot \frac{\pi}{-4}} \]
    9. Simplified97.4%

      \[\leadsto \frac{1}{\frac{1}{\log \color{blue}{\left(\frac{f + \frac{4}{\pi}}{f}\right)}} \cdot \frac{\pi}{-4}} \]
    10. Taylor expanded in f around inf 5.3%

      \[\leadsto \frac{1}{\color{blue}{\left(0.25 \cdot \left(f \cdot \pi\right)\right)} \cdot \frac{\pi}{-4}} \]
    11. Step-by-step derivation
      1. *-commutative5.3%

        \[\leadsto \frac{1}{\color{blue}{\left(\left(f \cdot \pi\right) \cdot 0.25\right)} \cdot \frac{\pi}{-4}} \]
    12. Simplified5.3%

      \[\leadsto \frac{1}{\color{blue}{\left(\left(f \cdot \pi\right) \cdot 0.25\right)} \cdot \frac{\pi}{-4}} \]

    if 230 < f

    1. Initial program 0.0%

      \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
    2. Simplified100.0%

      \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
    3. Add Preprocessing
    4. Applied egg-rr3.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
    5. Step-by-step derivation
      1. flip-+0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
      2. log-div0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
    6. Applied egg-rr0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
    7. Step-by-step derivation
      1. +-inverses0.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
      2. div00.0%

        \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
      3. +-inverses100.0%

        \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    8. Simplified100.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
    9. Step-by-step derivation
      1. add-log-exp100.0%

        \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
      2. metadata-eval100.0%

        \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
      3. associate-/r/100.0%

        \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
      4. exp-prod100.0%

        \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
      5. metadata-eval100.0%

        \[\leadsto \log \color{blue}{1} \]
      6. metadata-eval100.0%

        \[\leadsto \color{blue}{0} \]
    10. Applied egg-rr100.0%

      \[\leadsto \color{blue}{0} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification7.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;f \leq 230:\\ \;\;\;\;\frac{1}{\frac{\pi}{-4} \cdot \left(\left(\pi \cdot f\right) \cdot 0.25\right)}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
  5. Add Preprocessing

Alternative 11: 4.9% accurate, 532.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (f) :precision binary64 0.0)
double code(double f) {
	return 0.0;
}
real(8) function code(f)
    real(8), intent (in) :: f
    code = 0.0d0
end function
public static double code(double f) {
	return 0.0;
}
def code(f):
	return 0.0
function code(f)
	return 0.0
end
function tmp = code(f)
	tmp = 0.0;
end
code[f_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 6.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Simplified99.3%

    \[\leadsto \color{blue}{\log \left(\frac{-1}{\mathsf{expm1}\left(\left(-0.5 \cdot \pi\right) \cdot f\right)} + \frac{1}{\mathsf{expm1}\left(\left(0.5 \cdot \pi\right) \cdot f\right)}\right) \cdot \frac{-4}{\pi}} \]
  3. Add Preprocessing
  4. Applied egg-rr95.6%

    \[\leadsto \color{blue}{\frac{1}{\frac{\pi}{\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} + \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) \cdot -4}}} \]
  5. Step-by-step derivation
    1. flip-+0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\log \color{blue}{\left(\frac{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}{\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}}\right)} \cdot -4}} \]
    2. log-div0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} \cdot \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right) - \log \left(\frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)} - \frac{-1}{\mathsf{expm1}\left(\pi \cdot \left(-0.5 \cdot f\right)\right)}\right)\right)} \cdot -4}} \]
  6. Applied egg-rr0.0%

    \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{\left(\log \left(\frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}} - \frac{1}{{\left(\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)\right)}^{2}}\right) - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right)} \cdot -4}} \]
  7. Step-by-step derivation
    1. +-inverses0.0%

      \[\leadsto \frac{1}{\frac{\pi}{\left(\log \color{blue}{0} - \log \left(\frac{0}{\mathsf{expm1}\left(\pi \cdot \left(f \cdot -0.5\right)\right)}\right)\right) \cdot -4}} \]
    2. div00.0%

      \[\leadsto \frac{1}{\frac{\pi}{\left(\log 0 - \log \color{blue}{0}\right) \cdot -4}} \]
    3. +-inverses5.0%

      \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
  8. Simplified5.0%

    \[\leadsto \frac{1}{\frac{\pi}{\color{blue}{0} \cdot -4}} \]
  9. Step-by-step derivation
    1. add-log-exp5.0%

      \[\leadsto \color{blue}{\log \left(e^{\frac{1}{\frac{\pi}{0 \cdot -4}}}\right)} \]
    2. metadata-eval5.0%

      \[\leadsto \log \left(e^{\frac{1}{\frac{\pi}{\color{blue}{0}}}}\right) \]
    3. associate-/r/5.0%

      \[\leadsto \log \left(e^{\color{blue}{\frac{1}{\pi} \cdot 0}}\right) \]
    4. exp-prod5.0%

      \[\leadsto \log \color{blue}{\left({\left(e^{\frac{1}{\pi}}\right)}^{0}\right)} \]
    5. metadata-eval5.0%

      \[\leadsto \log \color{blue}{1} \]
    6. metadata-eval5.0%

      \[\leadsto \color{blue}{0} \]
  10. Applied egg-rr5.0%

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

Reproduce

?
herbie shell --seed 2024181 
(FPCore (f)
  :name "VandenBroeck and Keller, Equation (20)"
  :precision binary64
  (- (* (/ 1.0 (/ PI 4.0)) (log (/ (+ (exp (* (/ PI 4.0) f)) (exp (- (* (/ PI 4.0) f)))) (- (exp (* (/ PI 4.0) f)) (exp (- (* (/ PI 4.0) f)))))))))