VandenBroeck and Keller, Equation (20)

Percentage Accurate: 6.8% → 99.0%
Time: 18.9s
Alternatives: 6
Speedup: 4.9×

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 6 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: 99.0% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \frac{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}{\frac{\pi}{4}} \end{array} \]
(FPCore (f) :precision binary64 (/ (log (tanh (/ PI (/ 4.0 f)))) (/ PI 4.0)))
double code(double f) {
	return log(tanh((((double) M_PI) / (4.0 / f)))) / (((double) M_PI) / 4.0);
}
public static double code(double f) {
	return Math.log(Math.tanh((Math.PI / (4.0 / f)))) / (Math.PI / 4.0);
}
def code(f):
	return math.log(math.tanh((math.pi / (4.0 / f)))) / (math.pi / 4.0)
function code(f)
	return Float64(log(tanh(Float64(pi / Float64(4.0 / f)))) / Float64(pi / 4.0))
end
function tmp = code(f)
	tmp = log(tanh((pi / (4.0 / f)))) / (pi / 4.0);
end
code[f_] := N[(N[Log[N[Tanh[N[(Pi / N[(4.0 / f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] / N[(Pi / 4.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}{\frac{\pi}{4}}
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right) \cdot \frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}\right) \]
    2. un-div-invN/A

      \[\leadsto \mathsf{neg}\left(\frac{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\frac{\mathsf{PI}\left(\right)}{4}}\right) \]
    3. distribute-neg-fracN/A

      \[\leadsto \frac{\mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)\right)}{\color{blue}{\frac{\mathsf{PI}\left(\right)}{4}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)\right)\right), \color{blue}{\left(\frac{\mathsf{PI}\left(\right)}{4}\right)}\right) \]
  4. Applied egg-rr98.8%

    \[\leadsto \color{blue}{\frac{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}{\frac{\pi}{4}}} \]
  5. Add Preprocessing

Alternative 2: 98.9% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \frac{4}{\frac{\pi}{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}} \end{array} \]
(FPCore (f) :precision binary64 (/ 4.0 (/ PI (log (tanh (/ PI (/ 4.0 f)))))))
double code(double f) {
	return 4.0 / (((double) M_PI) / log(tanh((((double) M_PI) / (4.0 / f)))));
}
public static double code(double f) {
	return 4.0 / (Math.PI / Math.log(Math.tanh((Math.PI / (4.0 / f)))));
}
def code(f):
	return 4.0 / (math.pi / math.log(math.tanh((math.pi / (4.0 / f)))))
function code(f)
	return Float64(4.0 / Float64(pi / log(tanh(Float64(pi / Float64(4.0 / f))))))
end
function tmp = code(f)
	tmp = 4.0 / (pi / log(tanh((pi / (4.0 / f)))));
end
code[f_] := N[(4.0 / N[(Pi / N[Log[N[Tanh[N[(Pi / N[(4.0 / f), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{4}{\frac{\pi}{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}}
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right) \cdot \frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}\right) \]
    2. un-div-invN/A

      \[\leadsto \mathsf{neg}\left(\frac{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\frac{\mathsf{PI}\left(\right)}{4}}\right) \]
    3. distribute-neg-fracN/A

      \[\leadsto \frac{\mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)\right)}{\color{blue}{\frac{\mathsf{PI}\left(\right)}{4}}} \]
    4. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)\right)\right), \color{blue}{\left(\frac{\mathsf{PI}\left(\right)}{4}\right)}\right) \]
  4. Applied egg-rr98.8%

    \[\leadsto \color{blue}{\frac{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}{\frac{\pi}{4}}} \]
  5. Step-by-step derivation
    1. clear-numN/A

      \[\leadsto \frac{1}{\color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{4}}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}}} \]
    2. div-invN/A

      \[\leadsto \frac{1}{\frac{\mathsf{PI}\left(\right)}{4} \cdot \color{blue}{\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \frac{\frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}}{\color{blue}{\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}}} \]
    4. clear-numN/A

      \[\leadsto \frac{\frac{4}{\mathsf{PI}\left(\right)}}{\frac{\color{blue}{1}}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}} \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{4}{\mathsf{PI}\left(\right)}\right), \color{blue}{\left(\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)}\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI}\left(\right)\right), \left(\frac{\color{blue}{1}}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)\right) \]
    7. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \left(\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)\right) \]
    8. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \color{blue}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)\right) \]
    9. log-lowering-log.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \mathsf{log.f64}\left(\tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)\right)\right)\right) \]
    10. tanh-lowering-tanh.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)\right)\right)\right)\right) \]
    11. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI}\left(\right), \left(\frac{4}{f}\right)\right)\right)\right)\right)\right) \]
    12. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \left(\frac{4}{f}\right)\right)\right)\right)\right)\right) \]
    13. /-lowering-/.f6498.6%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{/.f64}\left(4, \mathsf{PI.f64}\left(\right)\right), \mathsf{/.f64}\left(1, \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{/.f64}\left(4, f\right)\right)\right)\right)\right)\right) \]
  6. Applied egg-rr98.6%

    \[\leadsto \color{blue}{\frac{\frac{4}{\pi}}{\frac{1}{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}}} \]
  7. Step-by-step derivation
    1. associate-/l/N/A

      \[\leadsto \frac{4}{\color{blue}{\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)} \cdot \mathsf{PI}\left(\right)}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \color{blue}{\left(\frac{1}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)} \cdot \mathsf{PI}\left(\right)\right)}\right) \]
    3. associate-*l/N/A

      \[\leadsto \mathsf{/.f64}\left(4, \left(\frac{1 \cdot \mathsf{PI}\left(\right)}{\color{blue}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}}\right)\right) \]
    4. *-un-lft-identityN/A

      \[\leadsto \mathsf{/.f64}\left(4, \left(\frac{\mathsf{PI}\left(\right)}{\log \color{blue}{\tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}}\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI}\left(\right), \color{blue}{\log \tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)\right) \]
    6. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \log \color{blue}{\tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)}\right)\right) \]
    7. log-lowering-log.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\tanh \left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)\right)\right)\right) \]
    8. tanh-lowering-tanh.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\left(\frac{\mathsf{PI}\left(\right)}{\frac{4}{f}}\right)\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI}\left(\right), \left(\frac{4}{f}\right)\right)\right)\right)\right)\right) \]
    10. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \left(\frac{4}{f}\right)\right)\right)\right)\right)\right) \]
    11. /-lowering-/.f6498.8%

      \[\leadsto \mathsf{/.f64}\left(4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{tanh.f64}\left(\mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{/.f64}\left(4, f\right)\right)\right)\right)\right)\right) \]
  8. Applied egg-rr98.8%

    \[\leadsto \color{blue}{\frac{4}{\frac{\pi}{\log \tanh \left(\frac{\pi}{\frac{4}{f}}\right)}}} \]
  9. Add Preprocessing

Alternative 3: 96.6% accurate, 4.2× speedup?

\[\begin{array}{l} \\ \frac{\log \left(\frac{\frac{4}{\pi} + \left(\pi \cdot 0.125 + -2 \cdot \frac{\left(\pi \cdot \pi\right) \cdot 0.020833333333333332}{\pi}\right) \cdot \left(f \cdot f\right)}{f}\right)}{\frac{\pi}{-4}} \end{array} \]
(FPCore (f)
 :precision binary64
 (/
  (log
   (/
    (+
     (/ 4.0 PI)
     (*
      (+ (* PI 0.125) (* -2.0 (/ (* (* PI PI) 0.020833333333333332) PI)))
      (* f f)))
    f))
  (/ PI -4.0)))
double code(double f) {
	return log((((4.0 / ((double) M_PI)) + (((((double) M_PI) * 0.125) + (-2.0 * (((((double) M_PI) * ((double) M_PI)) * 0.020833333333333332) / ((double) M_PI)))) * (f * f))) / f)) / (((double) M_PI) / -4.0);
}
public static double code(double f) {
	return Math.log((((4.0 / Math.PI) + (((Math.PI * 0.125) + (-2.0 * (((Math.PI * Math.PI) * 0.020833333333333332) / Math.PI))) * (f * f))) / f)) / (Math.PI / -4.0);
}
def code(f):
	return math.log((((4.0 / math.pi) + (((math.pi * 0.125) + (-2.0 * (((math.pi * math.pi) * 0.020833333333333332) / math.pi))) * (f * f))) / f)) / (math.pi / -4.0)
function code(f)
	return Float64(log(Float64(Float64(Float64(4.0 / pi) + Float64(Float64(Float64(pi * 0.125) + Float64(-2.0 * Float64(Float64(Float64(pi * pi) * 0.020833333333333332) / pi))) * Float64(f * f))) / f)) / Float64(pi / -4.0))
end
function tmp = code(f)
	tmp = log((((4.0 / pi) + (((pi * 0.125) + (-2.0 * (((pi * pi) * 0.020833333333333332) / pi))) * (f * f))) / f)) / (pi / -4.0);
end
code[f_] := N[(N[Log[N[(N[(N[(4.0 / Pi), $MachinePrecision] + N[(N[(N[(Pi * 0.125), $MachinePrecision] + N[(-2.0 * N[(N[(N[(Pi * Pi), $MachinePrecision] * 0.020833333333333332), $MachinePrecision] / Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(f * f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / f), $MachinePrecision]], $MachinePrecision] / N[(Pi / -4.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\log \left(\frac{\frac{4}{\pi} + \left(\pi \cdot 0.125 + -2 \cdot \frac{\left(\pi \cdot \pi\right) \cdot 0.020833333333333332}{\pi}\right) \cdot \left(f \cdot f\right)}{f}\right)}{\frac{\pi}{-4}}
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in f around 0

    \[\leadsto \mathsf{neg.f64}\left(\mathsf{*.f64}\left(\mathsf{/.f64}\left(1, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), 4\right)\right), \mathsf{log.f64}\left(\color{blue}{\left(\frac{f \cdot \left(\frac{-1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} + \left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} + f \cdot \left(\frac{1}{16} \cdot \frac{{\mathsf{PI}\left(\right)}^{2}}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} - 2 \cdot \frac{\frac{1}{384} \cdot {\mathsf{PI}\left(\right)}^{3} - \frac{-1}{384} \cdot {\mathsf{PI}\left(\right)}^{3}}{{\left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)}^{2}}\right)\right)\right) + 2 \cdot \frac{1}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}}{f}\right)}\right)\right)\right) \]
  4. Simplified95.5%

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \log \color{blue}{\left(\frac{\frac{2}{\pi \cdot 0.5} + f \cdot \left(f \cdot \left(0.0625 \cdot \left(\pi \cdot 2\right) + -2 \cdot \left(\left(\pi \cdot \left(\pi \cdot 2\right)\right) \cdot \frac{0.010416666666666666}{\pi}\right)\right)\right)}{f}\right)} \]
  5. Applied egg-rr95.6%

    \[\leadsto \color{blue}{\frac{\log \left(\frac{\frac{4}{\pi} + \left(\pi \cdot 0.125 + -2 \cdot \frac{\left(\pi \cdot \pi\right) \cdot 0.020833333333333332}{\pi}\right) \cdot \left(f \cdot f\right)}{f}\right)}{\frac{\pi}{-4}}} \]
  6. Add Preprocessing

Alternative 4: 96.1% accurate, 4.9× speedup?

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

\\
\frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\frac{\pi}{-4}}
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Step-by-step derivation
    1. distribute-lft-neg-inN/A

      \[\leadsto \left(\mathsf{neg}\left(\frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}\right)\right) \cdot \color{blue}{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    2. distribute-neg-frac2N/A

      \[\leadsto \frac{1}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)} \cdot \log \color{blue}{\left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    3. associate-*l/N/A

      \[\leadsto \frac{1 \cdot \log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\color{blue}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)}} \]
    4. *-lft-identityN/A

      \[\leadsto \frac{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\mathsf{neg}\left(\color{blue}{\frac{\mathsf{PI}\left(\right)}{4}}\right)} \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right), \color{blue}{\left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)\right)}\right) \]
  3. Simplified7.3%

    \[\leadsto \color{blue}{\frac{\log \left(\frac{e^{\pi \cdot \frac{f}{4}} + e^{\frac{\pi \cdot f}{-4}}}{e^{\pi \cdot \frac{f}{4}} - e^{\frac{\pi \cdot f}{-4}}}\right)}{\frac{\pi}{-4}}} \]
  4. Add Preprocessing
  5. Taylor expanded in f around 0

    \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(\frac{2}{f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)}\right)}\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    3. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \frac{1}{2}\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    5. associate-*l*N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{2} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(1 \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    7. *-inversesN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{\frac{1}{4}}{\frac{1}{2}}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    9. times-fracN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\mathsf{PI}\left(\right) \cdot \frac{1}{4}}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    12. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    13. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    15. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  7. Simplified94.8%

    \[\leadsto \frac{\log \color{blue}{\left(\frac{2}{\pi \cdot \left(f \cdot 0.5\right)}\right)}}{\frac{\pi}{-4}} \]
  8. Taylor expanded in f around 0

    \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(\frac{4}{f \cdot \mathsf{PI}\left(\right)}\right)}\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  9. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \left(f \cdot \mathsf{PI}\left(\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \mathsf{*.f64}\left(f, \mathsf{PI}\left(\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    3. PI-lowering-PI.f6494.8%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \mathsf{*.f64}\left(f, \mathsf{PI.f64}\left(\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  10. Simplified94.8%

    \[\leadsto \frac{\log \color{blue}{\left(\frac{4}{f \cdot \pi}\right)}}{\frac{\pi}{-4}} \]
  11. Final simplification94.8%

    \[\leadsto \frac{\log \left(\frac{4}{\pi \cdot f}\right)}{\frac{\pi}{-4}} \]
  12. Add Preprocessing

Alternative 5: 96.0% accurate, 4.9× speedup?

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

\\
\frac{-4}{\frac{\pi}{\log \left(\frac{4}{\pi \cdot f}\right)}}
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Step-by-step derivation
    1. distribute-lft-neg-inN/A

      \[\leadsto \left(\mathsf{neg}\left(\frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}\right)\right) \cdot \color{blue}{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    2. distribute-neg-frac2N/A

      \[\leadsto \frac{1}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)} \cdot \log \color{blue}{\left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    3. associate-*l/N/A

      \[\leadsto \frac{1 \cdot \log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\color{blue}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)}} \]
    4. *-lft-identityN/A

      \[\leadsto \frac{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\mathsf{neg}\left(\color{blue}{\frac{\mathsf{PI}\left(\right)}{4}}\right)} \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right), \color{blue}{\left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)\right)}\right) \]
  3. Simplified7.3%

    \[\leadsto \color{blue}{\frac{\log \left(\frac{e^{\pi \cdot \frac{f}{4}} + e^{\frac{\pi \cdot f}{-4}}}{e^{\pi \cdot \frac{f}{4}} - e^{\frac{\pi \cdot f}{-4}}}\right)}{\frac{\pi}{-4}}} \]
  4. Add Preprocessing
  5. Taylor expanded in f around 0

    \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(\frac{2}{f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)}\right)}\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    3. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \frac{1}{2}\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    5. associate-*l*N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{2} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(1 \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    7. *-inversesN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{\frac{1}{4}}{\frac{1}{2}}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    9. times-fracN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\mathsf{PI}\left(\right) \cdot \frac{1}{4}}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    12. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    13. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    15. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  7. Simplified94.8%

    \[\leadsto \frac{\log \color{blue}{\left(\frac{2}{\pi \cdot \left(f \cdot 0.5\right)}\right)}}{\frac{\pi}{-4}} \]
  8. Step-by-step derivation
    1. associate-/r*N/A

      \[\leadsto \mathsf{/.f64}\left(\log \left(\frac{\frac{2}{\mathsf{PI}\left(\right)}}{f \cdot \frac{1}{2}}\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    2. log-divN/A

      \[\leadsto \mathsf{/.f64}\left(\left(\log \left(\frac{2}{\mathsf{PI}\left(\right)}\right) - \log \left(f \cdot \frac{1}{2}\right)\right), \mathsf{/.f64}\left(\color{blue}{\mathsf{PI.f64}\left(\right)}, -4\right)\right) \]
    3. --lowering--.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right)}\right), \log \left(f \cdot \frac{1}{2}\right)\right), \mathsf{/.f64}\left(\color{blue}{\mathsf{PI.f64}\left(\right)}, -4\right)\right) \]
    4. log-lowering-log.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\mathsf{log.f64}\left(\left(\frac{2}{\mathsf{PI}\left(\right)}\right)\right), \log \left(f \cdot \frac{1}{2}\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{PI}\left(\right)\right)\right), \log \left(f \cdot \frac{1}{2}\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    6. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{PI.f64}\left(\right)\right)\right), \log \left(f \cdot \frac{1}{2}\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    7. log-lowering-log.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{PI.f64}\left(\right)\right)\right), \mathsf{log.f64}\left(\left(f \cdot \frac{1}{2}\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    8. *-lowering-*.f6494.7%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{\_.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{PI.f64}\left(\right)\right)\right), \mathsf{log.f64}\left(\mathsf{*.f64}\left(f, \frac{1}{2}\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  9. Applied egg-rr94.7%

    \[\leadsto \frac{\color{blue}{\log \left(\frac{2}{\pi}\right) - \log \left(f \cdot 0.5\right)}}{\frac{\pi}{-4}} \]
  10. Step-by-step derivation
    1. associate-/r/N/A

      \[\leadsto \frac{\log \left(\frac{2}{\mathsf{PI}\left(\right)}\right) - \log \left(f \cdot \frac{1}{2}\right)}{\mathsf{PI}\left(\right)} \cdot \color{blue}{-4} \]
    2. log-divN/A

      \[\leadsto \frac{\left(\log 2 - \log \mathsf{PI}\left(\right)\right) - \log \left(f \cdot \frac{1}{2}\right)}{\mathsf{PI}\left(\right)} \cdot -4 \]
    3. associate--l-N/A

      \[\leadsto \frac{\log 2 - \left(\log \mathsf{PI}\left(\right) + \log \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)} \cdot -4 \]
    4. log-prodN/A

      \[\leadsto \frac{\log 2 - \log \left(\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)} \cdot -4 \]
    5. sub-divN/A

      \[\leadsto \left(\frac{\log 2}{\mathsf{PI}\left(\right)} - \frac{\log \left(\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)}\right) \cdot -4 \]
    6. metadata-evalN/A

      \[\leadsto \left(\frac{\log 2}{\mathsf{PI}\left(\right)} - \frac{\log \left(\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)}\right) \cdot \frac{1}{\color{blue}{\frac{-1}{4}}} \]
    7. div-invN/A

      \[\leadsto \frac{\frac{\log 2}{\mathsf{PI}\left(\right)} - \frac{\log \left(\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)}}{\color{blue}{\frac{-1}{4}}} \]
    8. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{\log 2}{\mathsf{PI}\left(\right)} - \frac{\log \left(\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)\right)}{\mathsf{PI}\left(\right)}\right), \color{blue}{\frac{-1}{4}}\right) \]
  11. Applied egg-rr94.8%

    \[\leadsto \color{blue}{\frac{\frac{\log \left(\frac{\frac{4}{\pi}}{f}\right)}{\pi}}{-0.25}} \]
  12. Step-by-step derivation
    1. div-invN/A

      \[\leadsto \frac{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}{\mathsf{PI}\left(\right)} \cdot \color{blue}{\frac{1}{\frac{-1}{4}}} \]
    2. clear-numN/A

      \[\leadsto \frac{1}{\frac{\mathsf{PI}\left(\right)}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}} \cdot \frac{\color{blue}{1}}{\frac{-1}{4}} \]
    3. metadata-evalN/A

      \[\leadsto \frac{1}{\frac{\mathsf{PI}\left(\right)}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}} \cdot -4 \]
    4. associate-*l/N/A

      \[\leadsto \frac{1 \cdot -4}{\color{blue}{\frac{\mathsf{PI}\left(\right)}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}}} \]
    5. metadata-evalN/A

      \[\leadsto \frac{-4}{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}} \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \color{blue}{\left(\frac{\mathsf{PI}\left(\right)}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}\right)}\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI}\left(\right), \color{blue}{\log \left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}\right)\right) \]
    8. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \log \color{blue}{\left(\frac{\frac{4}{\mathsf{PI}\left(\right)}}{f}\right)}\right)\right) \]
    9. associate-/l/N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \log \left(\frac{4}{f \cdot \mathsf{PI}\left(\right)}\right)\right)\right) \]
    10. associate-/r*N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \log \left(\frac{\frac{4}{f}}{\mathsf{PI}\left(\right)}\right)\right)\right) \]
    11. log-lowering-log.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\left(\frac{\frac{4}{f}}{\mathsf{PI}\left(\right)}\right)\right)\right)\right) \]
    12. associate-/r*N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\left(\frac{4}{f \cdot \mathsf{PI}\left(\right)}\right)\right)\right)\right) \]
    13. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \left(f \cdot \mathsf{PI}\left(\right)\right)\right)\right)\right)\right) \]
    14. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \left(\mathsf{PI}\left(\right) \cdot f\right)\right)\right)\right)\right) \]
    15. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \mathsf{*.f64}\left(\mathsf{PI}\left(\right), f\right)\right)\right)\right)\right) \]
    16. PI-lowering-PI.f6494.8%

      \[\leadsto \mathsf{/.f64}\left(-4, \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), \mathsf{log.f64}\left(\mathsf{/.f64}\left(4, \mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), f\right)\right)\right)\right)\right) \]
  13. Applied egg-rr94.8%

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

Alternative 6: 96.0% accurate, 4.9× speedup?

\[\begin{array}{l} \\ \frac{4}{\pi} \cdot \log \left(\left(\pi \cdot f\right) \cdot 0.25\right) \end{array} \]
(FPCore (f) :precision binary64 (* (/ 4.0 PI) (log (* (* PI f) 0.25))))
double code(double f) {
	return (4.0 / ((double) M_PI)) * log(((((double) M_PI) * f) * 0.25));
}
public static double code(double f) {
	return (4.0 / Math.PI) * Math.log(((Math.PI * f) * 0.25));
}
def code(f):
	return (4.0 / math.pi) * math.log(((math.pi * f) * 0.25))
function code(f)
	return Float64(Float64(4.0 / pi) * log(Float64(Float64(pi * f) * 0.25)))
end
function tmp = code(f)
	tmp = (4.0 / pi) * log(((pi * f) * 0.25));
end
code[f_] := N[(N[(4.0 / Pi), $MachinePrecision] * N[Log[N[(N[(Pi * f), $MachinePrecision] * 0.25), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{4}{\pi} \cdot \log \left(\left(\pi \cdot f\right) \cdot 0.25\right)
\end{array}
Derivation
  1. Initial program 7.3%

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right) \]
  2. Step-by-step derivation
    1. distribute-lft-neg-inN/A

      \[\leadsto \left(\mathsf{neg}\left(\frac{1}{\frac{\mathsf{PI}\left(\right)}{4}}\right)\right) \cdot \color{blue}{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    2. distribute-neg-frac2N/A

      \[\leadsto \frac{1}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)} \cdot \log \color{blue}{\left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)} \]
    3. associate-*l/N/A

      \[\leadsto \frac{1 \cdot \log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\color{blue}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)}} \]
    4. *-lft-identityN/A

      \[\leadsto \frac{\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right)}{\mathsf{neg}\left(\color{blue}{\frac{\mathsf{PI}\left(\right)}{4}}\right)} \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\log \left(\frac{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} + e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}{e^{\frac{\mathsf{PI}\left(\right)}{4} \cdot f} - e^{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4} \cdot f\right)}}\right), \color{blue}{\left(\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{4}\right)\right)}\right) \]
  3. Simplified7.3%

    \[\leadsto \color{blue}{\frac{\log \left(\frac{e^{\pi \cdot \frac{f}{4}} + e^{\frac{\pi \cdot f}{-4}}}{e^{\pi \cdot \frac{f}{4}} - e^{\frac{\pi \cdot f}{-4}}}\right)}{\frac{\pi}{-4}}} \]
  4. Add Preprocessing
  5. Taylor expanded in f around 0

    \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\color{blue}{\left(\frac{2}{f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)}\right)}\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(f \cdot \left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    3. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\left(\mathsf{PI}\left(\right) \cdot \frac{1}{2}\right) \cdot f\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    5. associate-*l*N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{1}{2} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(1 \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    7. *-inversesN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{1}{2}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{\mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right)} \cdot \frac{\frac{1}{4}}{\frac{1}{2}}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    9. times-fracN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\mathsf{PI}\left(\right) \cdot \frac{1}{4}}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \frac{1}{2}} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\mathsf{PI}\left(\right) \cdot \left(\frac{1}{4} - \frac{-1}{4}\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    12. distribute-rgt-out--N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\frac{\frac{1}{4} \cdot \mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)} \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    13. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \left(\mathsf{PI}\left(\right) \cdot \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
    15. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{log.f64}\left(\mathsf{/.f64}\left(2, \mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), \left(\left(\frac{1}{4} \cdot \frac{\mathsf{PI}\left(\right)}{\frac{1}{4} \cdot \mathsf{PI}\left(\right) - \frac{-1}{4} \cdot \mathsf{PI}\left(\right)}\right) \cdot f\right)\right)\right)\right), \mathsf{/.f64}\left(\mathsf{PI.f64}\left(\right), -4\right)\right) \]
  7. Simplified94.8%

    \[\leadsto \frac{\log \color{blue}{\left(\frac{2}{\pi \cdot \left(f \cdot 0.5\right)}\right)}}{\frac{\pi}{-4}} \]
  8. Step-by-step derivation
    1. frac-2negN/A

      \[\leadsto \frac{\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)}{\color{blue}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{-4}\right)}} \]
    2. div-invN/A

      \[\leadsto \left(\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)\right) \cdot \color{blue}{\frac{1}{\mathsf{neg}\left(\frac{\mathsf{PI}\left(\right)}{-4}\right)}} \]
    3. distribute-neg-frac2N/A

      \[\leadsto \left(\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)\right) \cdot \frac{1}{\frac{\mathsf{PI}\left(\right)}{\color{blue}{\mathsf{neg}\left(-4\right)}}} \]
    4. metadata-evalN/A

      \[\leadsto \left(\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)\right) \cdot \frac{1}{\frac{\mathsf{PI}\left(\right)}{4}} \]
    5. clear-numN/A

      \[\leadsto \left(\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)\right) \cdot \frac{4}{\color{blue}{\mathsf{PI}\left(\right)}} \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\mathsf{neg}\left(\log \left(\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}\right)\right)\right), \color{blue}{\left(\frac{4}{\mathsf{PI}\left(\right)}\right)}\right) \]
    7. neg-logN/A

      \[\leadsto \mathsf{*.f64}\left(\log \left(\frac{1}{\frac{2}{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}}\right), \left(\frac{\color{blue}{4}}{\mathsf{PI}\left(\right)}\right)\right) \]
    8. clear-numN/A

      \[\leadsto \mathsf{*.f64}\left(\log \left(\frac{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}{2}\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    9. log-lowering-log.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\left(\frac{\mathsf{PI}\left(\right) \cdot \left(f \cdot \frac{1}{2}\right)}{2}\right)\right), \left(\frac{\color{blue}{4}}{\mathsf{PI}\left(\right)}\right)\right) \]
    10. associate-*r*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\left(\frac{\left(\mathsf{PI}\left(\right) \cdot f\right) \cdot \frac{1}{2}}{2}\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    11. associate-/l*N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\left(\left(\mathsf{PI}\left(\right) \cdot f\right) \cdot \frac{\frac{1}{2}}{2}\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\left(\left(\mathsf{PI}\left(\right) \cdot f\right) \cdot \frac{1}{4}\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    13. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\left(\left(\mathsf{PI}\left(\right) \cdot f\right) \cdot \frac{1}{4}\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\mathsf{*.f64}\left(\left(\mathsf{PI}\left(\right) \cdot f\right), \left(\frac{1}{4}\right)\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    15. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{PI}\left(\right), f\right), \left(\frac{1}{4}\right)\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    16. PI-lowering-PI.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), f\right), \left(\frac{1}{4}\right)\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    17. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), f\right), \frac{1}{4}\right)\right), \left(\frac{4}{\mathsf{PI}\left(\right)}\right)\right) \]
    18. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{log.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{PI.f64}\left(\right), f\right), \frac{1}{4}\right)\right), \mathsf{/.f64}\left(4, \color{blue}{\mathsf{PI}\left(\right)}\right)\right) \]
  9. Applied egg-rr94.7%

    \[\leadsto \color{blue}{\log \left(\left(\pi \cdot f\right) \cdot 0.25\right) \cdot \frac{4}{\pi}} \]
  10. Final simplification94.7%

    \[\leadsto \frac{4}{\pi} \cdot \log \left(\left(\pi \cdot f\right) \cdot 0.25\right) \]
  11. Add Preprocessing

Reproduce

?
herbie shell --seed 2024139 
(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)))))))))