NMSE Section 6.1 mentioned, B

Percentage Accurate: 78.2% → 99.7%
Time: 11.0s
Alternatives: 6
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \end{array} \]
(FPCore (a b)
 :precision binary64
 (* (* (/ PI 2.0) (/ 1.0 (- (* b b) (* a a)))) (- (/ 1.0 a) (/ 1.0 b))))
double code(double a, double b) {
	return ((((double) M_PI) / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
}
public static double code(double a, double b) {
	return ((Math.PI / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
}
def code(a, b):
	return ((math.pi / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b))
function code(a, b)
	return Float64(Float64(Float64(pi / 2.0) * Float64(1.0 / Float64(Float64(b * b) - Float64(a * a)))) * Float64(Float64(1.0 / a) - Float64(1.0 / b)))
end
function tmp = code(a, b)
	tmp = ((pi / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
end
code[a_, b_] := N[(N[(N[(Pi / 2.0), $MachinePrecision] * N[(1.0 / N[(N[(b * b), $MachinePrecision] - N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(1.0 / a), $MachinePrecision] - N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)
\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: 78.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \end{array} \]
(FPCore (a b)
 :precision binary64
 (* (* (/ PI 2.0) (/ 1.0 (- (* b b) (* a a)))) (- (/ 1.0 a) (/ 1.0 b))))
double code(double a, double b) {
	return ((((double) M_PI) / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
}
public static double code(double a, double b) {
	return ((Math.PI / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
}
def code(a, b):
	return ((math.pi / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b))
function code(a, b)
	return Float64(Float64(Float64(pi / 2.0) * Float64(1.0 / Float64(Float64(b * b) - Float64(a * a)))) * Float64(Float64(1.0 / a) - Float64(1.0 / b)))
end
function tmp = code(a, b)
	tmp = ((pi / 2.0) * (1.0 / ((b * b) - (a * a)))) * ((1.0 / a) - (1.0 / b));
end
code[a_, b_] := N[(N[(N[(Pi / 2.0), $MachinePrecision] * N[(1.0 / N[(N[(b * b), $MachinePrecision] - N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(1.0 / a), $MachinePrecision] - N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)
\end{array}

Alternative 1: 99.7% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{\frac{\pi}{a \cdot b}}{2 \cdot \left(a + b\right)} \end{array} \]
(FPCore (a b) :precision binary64 (/ (/ PI (* a b)) (* 2.0 (+ a b))))
double code(double a, double b) {
	return (((double) M_PI) / (a * b)) / (2.0 * (a + b));
}
public static double code(double a, double b) {
	return (Math.PI / (a * b)) / (2.0 * (a + b));
}
def code(a, b):
	return (math.pi / (a * b)) / (2.0 * (a + b))
function code(a, b)
	return Float64(Float64(pi / Float64(a * b)) / Float64(2.0 * Float64(a + b)))
end
function tmp = code(a, b)
	tmp = (pi / (a * b)) / (2.0 * (a + b));
end
code[a_, b_] := N[(N[(Pi / N[(a * b), $MachinePrecision]), $MachinePrecision] / N[(2.0 * N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\pi}{a \cdot b}}{2 \cdot \left(a + b\right)}
\end{array}
Derivation
  1. Initial program 74.3%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. inv-pow74.3%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares84.4%

      \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. unpow-prod-down85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. inv-pow85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. inv-pow85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  3. Applied egg-rr85.1%

    \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Step-by-step derivation
    1. associate-*r/85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. *-rgt-identity85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. +-commutative85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Simplified85.2%

    \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  6. Step-by-step derivation
    1. pow185.2%

      \[\leadsto \color{blue}{{\left(\left(\frac{\pi}{2} \cdot \frac{\frac{1}{a + b}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1}} \]
    2. frac-times85.2%

      \[\leadsto {\left(\color{blue}{\frac{\pi \cdot \frac{1}{a + b}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
    3. div-inv85.2%

      \[\leadsto {\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{2 \cdot \left(b - a\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
    4. inv-pow85.2%

      \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left(\color{blue}{{a}^{-1}} - \frac{1}{b}\right)\right)}^{1} \]
    5. inv-pow85.2%

      \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - \color{blue}{{b}^{-1}}\right)\right)}^{1} \]
  7. Applied egg-rr85.2%

    \[\leadsto \color{blue}{{\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)}^{1}} \]
  8. Step-by-step derivation
    1. unpow185.2%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left({a}^{-1} - {b}^{-1}\right)}{2 \cdot \left(b - a\right)}} \]
    3. times-frac99.6%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{{a}^{-1} - {b}^{-1}}{b - a}} \]
    4. unpow-199.6%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\color{blue}{\frac{1}{a}} - {b}^{-1}}{b - a} \]
    5. unpow-199.6%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \color{blue}{\frac{1}{b}}}{b - a} \]
  9. Simplified99.6%

    \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
  10. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  11. Step-by-step derivation
    1. associate-/r*99.7%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
  12. Simplified99.7%

    \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
  13. Step-by-step derivation
    1. associate-/r*99.6%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    2. expm1-log1p-u78.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\frac{\pi}{a + b}}{2} \cdot \frac{1}{a \cdot b}\right)\right)} \]
    3. expm1-udef53.6%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{\frac{\pi}{a + b}}{2} \cdot \frac{1}{a \cdot b}\right)} - 1} \]
    4. *-commutative53.6%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{1}{a \cdot b} \cdot \frac{\frac{\pi}{a + b}}{2}}\right)} - 1 \]
    5. frac-times53.6%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{1 \cdot \frac{\pi}{a + b}}{\left(a \cdot b\right) \cdot 2}}\right)} - 1 \]
    6. *-un-lft-identity53.6%

      \[\leadsto e^{\mathsf{log1p}\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{\left(a \cdot b\right) \cdot 2}\right)} - 1 \]
  14. Applied egg-rr53.6%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{\frac{\pi}{a + b}}{\left(a \cdot b\right) \cdot 2}\right)} - 1} \]
  15. Step-by-step derivation
    1. expm1-def78.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\frac{\pi}{a + b}}{\left(a \cdot b\right) \cdot 2}\right)\right)} \]
    2. expm1-log1p99.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{\left(a \cdot b\right) \cdot 2}} \]
    3. associate-/l/98.9%

      \[\leadsto \color{blue}{\frac{\pi}{\left(\left(a \cdot b\right) \cdot 2\right) \cdot \left(a + b\right)}} \]
    4. associate-*r*98.9%

      \[\leadsto \frac{\pi}{\color{blue}{\left(a \cdot b\right) \cdot \left(2 \cdot \left(a + b\right)\right)}} \]
    5. associate-/r*99.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a \cdot b}}{2 \cdot \left(a + b\right)}} \]
  16. Simplified99.7%

    \[\leadsto \color{blue}{\frac{\frac{\pi}{a \cdot b}}{2 \cdot \left(a + b\right)}} \]
  17. Final simplification99.7%

    \[\leadsto \frac{\frac{\pi}{a \cdot b}}{2 \cdot \left(a + b\right)} \]

Alternative 2: 66.9% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -6.8 \cdot 10^{-119}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -6.8e-119)
   (* (/ PI a) (/ (/ 0.5 a) b))
   (* (/ PI a) (/ 0.5 (* b b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -6.8e-119) {
		tmp = (((double) M_PI) / a) * ((0.5 / a) / b);
	} else {
		tmp = (((double) M_PI) / a) * (0.5 / (b * b));
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (a <= -6.8e-119) {
		tmp = (Math.PI / a) * ((0.5 / a) / b);
	} else {
		tmp = (Math.PI / a) * (0.5 / (b * b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -6.8e-119:
		tmp = (math.pi / a) * ((0.5 / a) / b)
	else:
		tmp = (math.pi / a) * (0.5 / (b * b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -6.8e-119)
		tmp = Float64(Float64(pi / a) * Float64(Float64(0.5 / a) / b));
	else
		tmp = Float64(Float64(pi / a) * Float64(0.5 / Float64(b * b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -6.8e-119)
		tmp = (pi / a) * ((0.5 / a) / b);
	else
		tmp = (pi / a) * (0.5 / (b * b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -6.8e-119], N[(N[(Pi / a), $MachinePrecision] * N[(N[(0.5 / a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision], N[(N[(Pi / a), $MachinePrecision] * N[(0.5 / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -6.8 \cdot 10^{-119}:\\
\;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -6.80000000000000047e-119

    1. Initial program 72.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. inv-pow72.4%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares87.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. unpow-prod-down89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. inv-pow89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. inv-pow89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. Applied egg-rr89.0%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Step-by-step derivation
      1. associate-*r/89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. *-rgt-identity89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. +-commutative89.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Simplified89.0%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Step-by-step derivation
      1. pow189.0%

        \[\leadsto \color{blue}{{\left(\left(\frac{\pi}{2} \cdot \frac{\frac{1}{a + b}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1}} \]
      2. frac-times89.0%

        \[\leadsto {\left(\color{blue}{\frac{\pi \cdot \frac{1}{a + b}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      3. div-inv89.0%

        \[\leadsto {\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{2 \cdot \left(b - a\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      4. inv-pow89.0%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left(\color{blue}{{a}^{-1}} - \frac{1}{b}\right)\right)}^{1} \]
      5. inv-pow89.0%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - \color{blue}{{b}^{-1}}\right)\right)}^{1} \]
    7. Applied egg-rr89.0%

      \[\leadsto \color{blue}{{\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)}^{1}} \]
    8. Step-by-step derivation
      1. unpow189.0%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)} \]
      2. associate-*l/99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left({a}^{-1} - {b}^{-1}\right)}{2 \cdot \left(b - a\right)}} \]
      3. times-frac99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{{a}^{-1} - {b}^{-1}}{b - a}} \]
      4. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\color{blue}{\frac{1}{a}} - {b}^{-1}}{b - a} \]
      5. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \color{blue}{\frac{1}{b}}}{b - a} \]
    9. Simplified99.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    10. Taylor expanded in a around 0 99.7%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    11. Step-by-step derivation
      1. associate-/r*99.8%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    12. Simplified99.8%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    13. Taylor expanded in a around inf 69.4%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{{a}^{2} \cdot b}} \]
    14. Step-by-step derivation
      1. associate-*r/69.4%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{{a}^{2} \cdot b}} \]
      2. unpow269.4%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(a \cdot a\right)} \cdot b} \]
      3. *-commutative69.4%

        \[\leadsto \frac{\color{blue}{\pi \cdot 0.5}}{\left(a \cdot a\right) \cdot b} \]
      4. associate-*l*76.2%

        \[\leadsto \frac{\pi \cdot 0.5}{\color{blue}{a \cdot \left(a \cdot b\right)}} \]
      5. associate-/r*76.2%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{a}}{a \cdot b}} \]
      6. associate-*r/76.2%

        \[\leadsto \frac{\color{blue}{\pi \cdot \frac{0.5}{a}}}{a \cdot b} \]
      7. times-frac76.3%

        \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]
    15. Simplified76.3%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]

    if -6.80000000000000047e-119 < a

    1. Initial program 75.5%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. inv-pow75.5%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares82.4%

        \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. unpow-prod-down82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. inv-pow82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. inv-pow82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. Applied egg-rr82.8%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Step-by-step derivation
      1. associate-*r/82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. *-rgt-identity82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. +-commutative82.8%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Simplified82.8%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Taylor expanded in a around 0 58.5%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{a \cdot {b}^{2}}} \]
    7. Step-by-step derivation
      1. associate-*r/58.5%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot {b}^{2}}} \]
      2. *-commutative58.5%

        \[\leadsto \frac{\color{blue}{\pi \cdot 0.5}}{a \cdot {b}^{2}} \]
      3. times-frac58.5%

        \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{{b}^{2}}} \]
      4. unpow258.5%

        \[\leadsto \frac{\pi}{a} \cdot \frac{0.5}{\color{blue}{b \cdot b}} \]
    8. Simplified58.5%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification65.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -6.8 \cdot 10^{-119}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}\\ \end{array} \]

Alternative 3: 74.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.8 \cdot 10^{-61}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{0.5}{a \cdot b}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -1.8e-61)
   (* (/ PI a) (/ (/ 0.5 a) b))
   (* (/ PI b) (/ 0.5 (* a b)))))
double code(double a, double b) {
	double tmp;
	if (a <= -1.8e-61) {
		tmp = (((double) M_PI) / a) * ((0.5 / a) / b);
	} else {
		tmp = (((double) M_PI) / b) * (0.5 / (a * b));
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (a <= -1.8e-61) {
		tmp = (Math.PI / a) * ((0.5 / a) / b);
	} else {
		tmp = (Math.PI / b) * (0.5 / (a * b));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -1.8e-61:
		tmp = (math.pi / a) * ((0.5 / a) / b)
	else:
		tmp = (math.pi / b) * (0.5 / (a * b))
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -1.8e-61)
		tmp = Float64(Float64(pi / a) * Float64(Float64(0.5 / a) / b));
	else
		tmp = Float64(Float64(pi / b) * Float64(0.5 / Float64(a * b)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -1.8e-61)
		tmp = (pi / a) * ((0.5 / a) / b);
	else
		tmp = (pi / b) * (0.5 / (a * b));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -1.8e-61], N[(N[(Pi / a), $MachinePrecision] * N[(N[(0.5 / a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision], N[(N[(Pi / b), $MachinePrecision] * N[(0.5 / N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.8 \cdot 10^{-61}:\\
\;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{\pi}{b} \cdot \frac{0.5}{a \cdot b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.80000000000000007e-61

    1. Initial program 70.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. inv-pow70.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares89.4%

        \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. unpow-prod-down89.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. inv-pow89.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. inv-pow89.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. Applied egg-rr89.9%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Step-by-step derivation
      1. associate-*r/90.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. *-rgt-identity90.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. +-commutative90.0%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Simplified90.0%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Step-by-step derivation
      1. pow190.0%

        \[\leadsto \color{blue}{{\left(\left(\frac{\pi}{2} \cdot \frac{\frac{1}{a + b}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1}} \]
      2. frac-times90.0%

        \[\leadsto {\left(\color{blue}{\frac{\pi \cdot \frac{1}{a + b}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      3. div-inv89.9%

        \[\leadsto {\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{2 \cdot \left(b - a\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      4. inv-pow89.9%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left(\color{blue}{{a}^{-1}} - \frac{1}{b}\right)\right)}^{1} \]
      5. inv-pow89.9%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - \color{blue}{{b}^{-1}}\right)\right)}^{1} \]
    7. Applied egg-rr89.9%

      \[\leadsto \color{blue}{{\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)}^{1}} \]
    8. Step-by-step derivation
      1. unpow189.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)} \]
      2. associate-*l/99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left({a}^{-1} - {b}^{-1}\right)}{2 \cdot \left(b - a\right)}} \]
      3. times-frac99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{{a}^{-1} - {b}^{-1}}{b - a}} \]
      4. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\color{blue}{\frac{1}{a}} - {b}^{-1}}{b - a} \]
      5. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \color{blue}{\frac{1}{b}}}{b - a} \]
    9. Simplified99.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    10. Taylor expanded in a around 0 99.7%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    11. Step-by-step derivation
      1. associate-/r*99.8%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    12. Simplified99.8%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    13. Taylor expanded in a around inf 76.4%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{{a}^{2} \cdot b}} \]
    14. Step-by-step derivation
      1. associate-*r/76.4%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{{a}^{2} \cdot b}} \]
      2. unpow276.4%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(a \cdot a\right)} \cdot b} \]
      3. *-commutative76.4%

        \[\leadsto \frac{\color{blue}{\pi \cdot 0.5}}{\left(a \cdot a\right) \cdot b} \]
      4. associate-*l*84.5%

        \[\leadsto \frac{\pi \cdot 0.5}{\color{blue}{a \cdot \left(a \cdot b\right)}} \]
      5. associate-/r*84.5%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{a}}{a \cdot b}} \]
      6. associate-*r/84.5%

        \[\leadsto \frac{\color{blue}{\pi \cdot \frac{0.5}{a}}}{a \cdot b} \]
      7. times-frac84.6%

        \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]
    15. Simplified84.6%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]

    if -1.80000000000000007e-61 < a

    1. Initial program 75.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. inv-pow75.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares82.1%

        \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. unpow-prod-down82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. inv-pow82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. inv-pow82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. Applied egg-rr82.9%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Step-by-step derivation
      1. associate-*r/82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. *-rgt-identity82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. +-commutative82.9%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Simplified82.9%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Step-by-step derivation
      1. pow182.9%

        \[\leadsto \color{blue}{{\left(\left(\frac{\pi}{2} \cdot \frac{\frac{1}{a + b}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1}} \]
      2. frac-times82.9%

        \[\leadsto {\left(\color{blue}{\frac{\pi \cdot \frac{1}{a + b}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      3. div-inv83.0%

        \[\leadsto {\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{2 \cdot \left(b - a\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      4. inv-pow83.0%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left(\color{blue}{{a}^{-1}} - \frac{1}{b}\right)\right)}^{1} \]
      5. inv-pow83.0%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - \color{blue}{{b}^{-1}}\right)\right)}^{1} \]
    7. Applied egg-rr83.0%

      \[\leadsto \color{blue}{{\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)}^{1}} \]
    8. Step-by-step derivation
      1. unpow183.0%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)} \]
      2. associate-*l/99.6%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left({a}^{-1} - {b}^{-1}\right)}{2 \cdot \left(b - a\right)}} \]
      3. times-frac99.6%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{{a}^{-1} - {b}^{-1}}{b - a}} \]
      4. unpow-199.6%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\color{blue}{\frac{1}{a}} - {b}^{-1}}{b - a} \]
      5. unpow-199.6%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \color{blue}{\frac{1}{b}}}{b - a} \]
    9. Simplified99.6%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    10. Taylor expanded in a around 0 57.8%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{a \cdot {b}^{2}}} \]
    11. Step-by-step derivation
      1. associate-*r/57.8%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot {b}^{2}}} \]
      2. unpow257.8%

        \[\leadsto \frac{0.5 \cdot \pi}{a \cdot \color{blue}{\left(b \cdot b\right)}} \]
      3. associate-*r*67.8%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(a \cdot b\right) \cdot b}} \]
      4. times-frac68.7%

        \[\leadsto \color{blue}{\frac{0.5}{a \cdot b} \cdot \frac{\pi}{b}} \]
      5. *-commutative68.7%

        \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{0.5}{a \cdot b}} \]
    12. Simplified68.7%

      \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{0.5}{a \cdot b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.8 \cdot 10^{-61}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{0.5}{a \cdot b}\\ \end{array} \]

Alternative 4: 75.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.2 \cdot 10^{-49}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\pi \cdot 0.5}{a \cdot b}}{b}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= a -1.2e-49)
   (* (/ PI a) (/ (/ 0.5 a) b))
   (/ (/ (* PI 0.5) (* a b)) b)))
double code(double a, double b) {
	double tmp;
	if (a <= -1.2e-49) {
		tmp = (((double) M_PI) / a) * ((0.5 / a) / b);
	} else {
		tmp = ((((double) M_PI) * 0.5) / (a * b)) / b;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (a <= -1.2e-49) {
		tmp = (Math.PI / a) * ((0.5 / a) / b);
	} else {
		tmp = ((Math.PI * 0.5) / (a * b)) / b;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if a <= -1.2e-49:
		tmp = (math.pi / a) * ((0.5 / a) / b)
	else:
		tmp = ((math.pi * 0.5) / (a * b)) / b
	return tmp
function code(a, b)
	tmp = 0.0
	if (a <= -1.2e-49)
		tmp = Float64(Float64(pi / a) * Float64(Float64(0.5 / a) / b));
	else
		tmp = Float64(Float64(Float64(pi * 0.5) / Float64(a * b)) / b);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (a <= -1.2e-49)
		tmp = (pi / a) * ((0.5 / a) / b);
	else
		tmp = ((pi * 0.5) / (a * b)) / b;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[a, -1.2e-49], N[(N[(Pi / a), $MachinePrecision] * N[(N[(0.5 / a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision], N[(N[(N[(Pi * 0.5), $MachinePrecision] / N[(a * b), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.2 \cdot 10^{-49}:\\
\;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\pi \cdot 0.5}{a \cdot b}}{b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.19999999999999996e-49

    1. Initial program 69.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. inv-pow69.4%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares89.6%

        \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. unpow-prod-down90.2%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. inv-pow90.2%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. inv-pow90.2%

        \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. Applied egg-rr90.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Step-by-step derivation
      1. associate-*r/90.3%

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. *-rgt-identity90.3%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. +-commutative90.3%

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Simplified90.3%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Step-by-step derivation
      1. pow190.3%

        \[\leadsto \color{blue}{{\left(\left(\frac{\pi}{2} \cdot \frac{\frac{1}{a + b}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1}} \]
      2. frac-times90.2%

        \[\leadsto {\left(\color{blue}{\frac{\pi \cdot \frac{1}{a + b}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      3. div-inv90.2%

        \[\leadsto {\left(\frac{\color{blue}{\frac{\pi}{a + b}}}{2 \cdot \left(b - a\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)}^{1} \]
      4. inv-pow90.2%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left(\color{blue}{{a}^{-1}} - \frac{1}{b}\right)\right)}^{1} \]
      5. inv-pow90.2%

        \[\leadsto {\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - \color{blue}{{b}^{-1}}\right)\right)}^{1} \]
    7. Applied egg-rr90.2%

      \[\leadsto \color{blue}{{\left(\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)}^{1}} \]
    8. Step-by-step derivation
      1. unpow190.2%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2 \cdot \left(b - a\right)} \cdot \left({a}^{-1} - {b}^{-1}\right)} \]
      2. associate-*l/99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left({a}^{-1} - {b}^{-1}\right)}{2 \cdot \left(b - a\right)}} \]
      3. times-frac99.7%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{{a}^{-1} - {b}^{-1}}{b - a}} \]
      4. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\color{blue}{\frac{1}{a}} - {b}^{-1}}{b - a} \]
      5. unpow-199.7%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \color{blue}{\frac{1}{b}}}{b - a} \]
    9. Simplified99.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b}}{2} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    10. Taylor expanded in a around 0 99.7%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    11. Step-by-step derivation
      1. associate-/r*99.8%

        \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    12. Simplified99.8%

      \[\leadsto \frac{\frac{\pi}{a + b}}{2} \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    13. Taylor expanded in a around inf 79.3%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{{a}^{2} \cdot b}} \]
    14. Step-by-step derivation
      1. associate-*r/79.3%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{{a}^{2} \cdot b}} \]
      2. unpow279.3%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(a \cdot a\right)} \cdot b} \]
      3. *-commutative79.3%

        \[\leadsto \frac{\color{blue}{\pi \cdot 0.5}}{\left(a \cdot a\right) \cdot b} \]
      4. associate-*l*88.2%

        \[\leadsto \frac{\pi \cdot 0.5}{\color{blue}{a \cdot \left(a \cdot b\right)}} \]
      5. associate-/r*88.2%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{a}}{a \cdot b}} \]
      6. associate-*r/88.2%

        \[\leadsto \frac{\color{blue}{\pi \cdot \frac{0.5}{a}}}{a \cdot b} \]
      7. times-frac88.3%

        \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]
    15. Simplified88.3%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}} \]

    if -1.19999999999999996e-49 < a

    1. Initial program 76.3%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Taylor expanded in b around inf 57.3%

      \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{a \cdot {b}^{2}}} \]
    3. Step-by-step derivation
      1. associate-*r/57.3%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot {b}^{2}}} \]
      2. unpow257.3%

        \[\leadsto \frac{0.5 \cdot \pi}{a \cdot \color{blue}{\left(b \cdot b\right)}} \]
    4. Simplified57.3%

      \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot \left(b \cdot b\right)}} \]
    5. Step-by-step derivation
      1. times-frac57.3%

        \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot b}} \]
    6. Applied egg-rr57.3%

      \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot b}} \]
    7. Step-by-step derivation
      1. frac-times57.3%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot \left(b \cdot b\right)}} \]
      2. associate-*l*67.5%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(a \cdot b\right) \cdot b}} \]
      3. associate-/r*68.5%

        \[\leadsto \color{blue}{\frac{\frac{0.5 \cdot \pi}{a \cdot b}}{b}} \]
      4. *-commutative68.5%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot 0.5}}{a \cdot b}}{b} \]
    8. Applied egg-rr68.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{a \cdot b}}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.2 \cdot 10^{-49}:\\ \;\;\;\;\frac{\pi}{a} \cdot \frac{\frac{0.5}{a}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\pi \cdot 0.5}{a \cdot b}}{b}\\ \end{array} \]

Alternative 5: 57.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{0.5}{a} \cdot \frac{\pi}{b \cdot b} \end{array} \]
(FPCore (a b) :precision binary64 (* (/ 0.5 a) (/ PI (* b b))))
double code(double a, double b) {
	return (0.5 / a) * (((double) M_PI) / (b * b));
}
public static double code(double a, double b) {
	return (0.5 / a) * (Math.PI / (b * b));
}
def code(a, b):
	return (0.5 / a) * (math.pi / (b * b))
function code(a, b)
	return Float64(Float64(0.5 / a) * Float64(pi / Float64(b * b)))
end
function tmp = code(a, b)
	tmp = (0.5 / a) * (pi / (b * b));
end
code[a_, b_] := N[(N[(0.5 / a), $MachinePrecision] * N[(Pi / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.5}{a} \cdot \frac{\pi}{b \cdot b}
\end{array}
Derivation
  1. Initial program 74.3%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Taylor expanded in b around inf 54.9%

    \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{a \cdot {b}^{2}}} \]
  3. Step-by-step derivation
    1. associate-*r/54.9%

      \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot {b}^{2}}} \]
    2. unpow254.9%

      \[\leadsto \frac{0.5 \cdot \pi}{a \cdot \color{blue}{\left(b \cdot b\right)}} \]
  4. Simplified54.9%

    \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot \left(b \cdot b\right)}} \]
  5. Step-by-step derivation
    1. times-frac54.7%

      \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot b}} \]
  6. Applied egg-rr54.7%

    \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot b}} \]
  7. Final simplification54.7%

    \[\leadsto \frac{0.5}{a} \cdot \frac{\pi}{b \cdot b} \]

Alternative 6: 57.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{\pi}{a} \cdot \frac{0.5}{b \cdot b} \end{array} \]
(FPCore (a b) :precision binary64 (* (/ PI a) (/ 0.5 (* b b))))
double code(double a, double b) {
	return (((double) M_PI) / a) * (0.5 / (b * b));
}
public static double code(double a, double b) {
	return (Math.PI / a) * (0.5 / (b * b));
}
def code(a, b):
	return (math.pi / a) * (0.5 / (b * b))
function code(a, b)
	return Float64(Float64(pi / a) * Float64(0.5 / Float64(b * b)))
end
function tmp = code(a, b)
	tmp = (pi / a) * (0.5 / (b * b));
end
code[a_, b_] := N[(N[(Pi / a), $MachinePrecision] * N[(0.5 / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}
\end{array}
Derivation
  1. Initial program 74.3%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. inv-pow74.3%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{{\left(b \cdot b - a \cdot a\right)}^{-1}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares84.4%

      \[\leadsto \left(\frac{\pi}{2} \cdot {\color{blue}{\left(\left(b + a\right) \cdot \left(b - a\right)\right)}}^{-1}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. unpow-prod-down85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left({\left(b + a\right)}^{-1} \cdot {\left(b - a\right)}^{-1}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. inv-pow85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{b + a}} \cdot {\left(b - a\right)}^{-1}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. inv-pow85.1%

      \[\leadsto \left(\frac{\pi}{2} \cdot \left(\frac{1}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right)\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  3. Applied egg-rr85.1%

    \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\left(\frac{1}{b + a} \cdot \frac{1}{b - a}\right)}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Step-by-step derivation
    1. associate-*r/85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{b + a} \cdot 1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. *-rgt-identity85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{b + a}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. +-commutative85.2%

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{\frac{1}{\color{blue}{a + b}}}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Simplified85.2%

    \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{\frac{1}{a + b}}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  6. Taylor expanded in a around 0 54.9%

    \[\leadsto \color{blue}{0.5 \cdot \frac{\pi}{a \cdot {b}^{2}}} \]
  7. Step-by-step derivation
    1. associate-*r/54.9%

      \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot {b}^{2}}} \]
    2. *-commutative54.9%

      \[\leadsto \frac{\color{blue}{\pi \cdot 0.5}}{a \cdot {b}^{2}} \]
    3. times-frac54.6%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{{b}^{2}}} \]
    4. unpow254.6%

      \[\leadsto \frac{\pi}{a} \cdot \frac{0.5}{\color{blue}{b \cdot b}} \]
  8. Simplified54.6%

    \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b \cdot b}} \]
  9. Final simplification54.6%

    \[\leadsto \frac{\pi}{a} \cdot \frac{0.5}{b \cdot b} \]

Reproduce

?
herbie shell --seed 2023275 
(FPCore (a b)
  :name "NMSE Section 6.1 mentioned, B"
  :precision binary64
  (* (* (/ PI 2.0) (/ 1.0 (- (* b b) (* a a)))) (- (/ 1.0 a) (/ 1.0 b))))