NMSE Section 6.1 mentioned, B

Percentage Accurate: 78.9% → 99.6%
Time: 10.0s
Alternatives: 4
Speedup: 1.9×

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 4 alternatives:

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

Initial Program: 78.9% 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: 99.6% accurate, 1.3× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \begin{array}{l} \mathbf{if}\;b \leq 8.8 \cdot 10^{+113}:\\ \;\;\;\;\frac{0.5}{a} \cdot \frac{\pi}{b \cdot \left(a + b\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{a \cdot b} \cdot \frac{\pi}{b}\\ \end{array} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b)
 :precision binary64
 (if (<= b 8.8e+113)
   (* (/ 0.5 a) (/ PI (* b (+ a b))))
   (* (/ 0.5 (* a b)) (/ PI b))))
assert(a < b);
double code(double a, double b) {
	double tmp;
	if (b <= 8.8e+113) {
		tmp = (0.5 / a) * (((double) M_PI) / (b * (a + b)));
	} else {
		tmp = (0.5 / (a * b)) * (((double) M_PI) / b);
	}
	return tmp;
}
assert a < b;
public static double code(double a, double b) {
	double tmp;
	if (b <= 8.8e+113) {
		tmp = (0.5 / a) * (Math.PI / (b * (a + b)));
	} else {
		tmp = (0.5 / (a * b)) * (Math.PI / b);
	}
	return tmp;
}
[a, b] = sort([a, b])
def code(a, b):
	tmp = 0
	if b <= 8.8e+113:
		tmp = (0.5 / a) * (math.pi / (b * (a + b)))
	else:
		tmp = (0.5 / (a * b)) * (math.pi / b)
	return tmp
a, b = sort([a, b])
function code(a, b)
	tmp = 0.0
	if (b <= 8.8e+113)
		tmp = Float64(Float64(0.5 / a) * Float64(pi / Float64(b * Float64(a + b))));
	else
		tmp = Float64(Float64(0.5 / Float64(a * b)) * Float64(pi / b));
	end
	return tmp
end
a, b = num2cell(sort([a, b])){:}
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 8.8e+113)
		tmp = (0.5 / a) * (pi / (b * (a + b)));
	else
		tmp = (0.5 / (a * b)) * (pi / b);
	end
	tmp_2 = tmp;
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := If[LessEqual[b, 8.8e+113], N[(N[(0.5 / a), $MachinePrecision] * N[(Pi / N[(b * N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 / N[(a * b), $MachinePrecision]), $MachinePrecision] * N[(Pi / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\begin{array}{l}
\mathbf{if}\;b \leq 8.8 \cdot 10^{+113}:\\
\;\;\;\;\frac{0.5}{a} \cdot \frac{\pi}{b \cdot \left(a + b\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 8.80000000000000041e113

    1. Initial program 79.6%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. *-commutative79.6%

        \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
      2. sub-neg79.6%

        \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      3. distribute-neg-frac79.6%

        \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      4. metadata-eval79.6%

        \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      5. *-commutative79.6%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
      6. associate-*r/79.6%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
      7. associate-*l/79.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
      8. *-lft-identity79.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\color{blue}{\pi}}{b \cdot b - a \cdot a}}{2} \]
      9. difference-of-squares86.9%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
      10. associate-/r*87.4%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
    3. Simplified87.4%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. *-commutative87.4%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
      2. associate-/l/87.4%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
      3. frac-add87.4%

        \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
      4. frac-times99.1%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      5. +-commutative99.1%

        \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      6. *-un-lft-identity99.1%

        \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. Applied egg-rr99.1%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    7. Step-by-step derivation
      1. associate-/l*99.1%

        \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      2. +-commutative99.1%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      3. fma-define99.1%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      4. associate-*l*99.1%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    8. Applied egg-rr99.1%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    9. Taylor expanded in a around 0 99.6%

      \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
    10. Step-by-step derivation
      1. frac-times99.2%

        \[\leadsto \color{blue}{\frac{\pi \cdot 0.5}{\left(a + b\right) \cdot \left(a \cdot b\right)}} \]
    11. Applied egg-rr99.2%

      \[\leadsto \color{blue}{\frac{\pi \cdot 0.5}{\left(a + b\right) \cdot \left(a \cdot b\right)}} \]
    12. Step-by-step derivation
      1. times-frac99.6%

        \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{0.5}{a \cdot b}} \]
      2. *-commutative99.6%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{0.5}{\color{blue}{b \cdot a}} \]
      3. associate-/l/99.6%

        \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{\frac{0.5}{a}}{b}} \]
      4. *-commutative99.6%

        \[\leadsto \color{blue}{\frac{\frac{0.5}{a}}{b} \cdot \frac{\pi}{a + b}} \]
      5. times-frac95.1%

        \[\leadsto \color{blue}{\frac{\frac{0.5}{a} \cdot \pi}{b \cdot \left(a + b\right)}} \]
      6. associate-/l*95.0%

        \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot \left(a + b\right)}} \]
    13. Simplified95.0%

      \[\leadsto \color{blue}{\frac{0.5}{a} \cdot \frac{\pi}{b \cdot \left(a + b\right)}} \]

    if 8.80000000000000041e113 < b

    1. Initial program 75.7%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. *-commutative75.7%

        \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
      2. sub-neg75.7%

        \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      3. distribute-neg-frac75.7%

        \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      4. metadata-eval75.7%

        \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      5. *-commutative75.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
      6. associate-*r/75.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
      7. associate-*l/75.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
      8. *-lft-identity75.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\color{blue}{\pi}}{b \cdot b - a \cdot a}}{2} \]
      9. difference-of-squares88.2%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
      10. associate-/r*88.1%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
    3. Simplified88.1%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. *-commutative88.1%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
      2. associate-/l/88.1%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
      3. frac-add88.1%

        \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
      4. frac-times99.8%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      5. +-commutative99.8%

        \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      6. *-un-lft-identity99.8%

        \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. Applied egg-rr99.8%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    7. Step-by-step derivation
      1. associate-/l*99.8%

        \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      2. +-commutative99.8%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      3. fma-define99.8%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      4. associate-*l*99.8%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    8. Applied egg-rr99.8%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    9. Taylor expanded in a around 0 99.8%

      \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
    10. Taylor expanded in a around 0 99.8%

      \[\leadsto \color{blue}{\frac{\pi}{b}} \cdot \frac{0.5}{a \cdot b} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 8.8 \cdot 10^{+113}:\\ \;\;\;\;\frac{0.5}{a} \cdot \frac{\pi}{b \cdot \left(a + b\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{a \cdot b} \cdot \frac{\pi}{b}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 88.5% accurate, 1.5× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \begin{array}{l} t_0 := \frac{0.5}{a \cdot b}\\ \mathbf{if}\;a \leq -2.7 \cdot 10^{+14}:\\ \;\;\;\;t\_0 \cdot \frac{\pi}{a}\\ \mathbf{else}:\\ \;\;\;\;t\_0 \cdot \frac{\pi}{b}\\ \end{array} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b)
 :precision binary64
 (let* ((t_0 (/ 0.5 (* a b))))
   (if (<= a -2.7e+14) (* t_0 (/ PI a)) (* t_0 (/ PI b)))))
assert(a < b);
double code(double a, double b) {
	double t_0 = 0.5 / (a * b);
	double tmp;
	if (a <= -2.7e+14) {
		tmp = t_0 * (((double) M_PI) / a);
	} else {
		tmp = t_0 * (((double) M_PI) / b);
	}
	return tmp;
}
assert a < b;
public static double code(double a, double b) {
	double t_0 = 0.5 / (a * b);
	double tmp;
	if (a <= -2.7e+14) {
		tmp = t_0 * (Math.PI / a);
	} else {
		tmp = t_0 * (Math.PI / b);
	}
	return tmp;
}
[a, b] = sort([a, b])
def code(a, b):
	t_0 = 0.5 / (a * b)
	tmp = 0
	if a <= -2.7e+14:
		tmp = t_0 * (math.pi / a)
	else:
		tmp = t_0 * (math.pi / b)
	return tmp
a, b = sort([a, b])
function code(a, b)
	t_0 = Float64(0.5 / Float64(a * b))
	tmp = 0.0
	if (a <= -2.7e+14)
		tmp = Float64(t_0 * Float64(pi / a));
	else
		tmp = Float64(t_0 * Float64(pi / b));
	end
	return tmp
end
a, b = num2cell(sort([a, b])){:}
function tmp_2 = code(a, b)
	t_0 = 0.5 / (a * b);
	tmp = 0.0;
	if (a <= -2.7e+14)
		tmp = t_0 * (pi / a);
	else
		tmp = t_0 * (pi / b);
	end
	tmp_2 = tmp;
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := Block[{t$95$0 = N[(0.5 / N[(a * b), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[a, -2.7e+14], N[(t$95$0 * N[(Pi / a), $MachinePrecision]), $MachinePrecision], N[(t$95$0 * N[(Pi / b), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\begin{array}{l}
t_0 := \frac{0.5}{a \cdot b}\\
\mathbf{if}\;a \leq -2.7 \cdot 10^{+14}:\\
\;\;\;\;t\_0 \cdot \frac{\pi}{a}\\

\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \frac{\pi}{b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -2.7e14

    1. Initial program 83.3%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. *-commutative83.3%

        \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
      2. sub-neg83.3%

        \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      3. distribute-neg-frac83.3%

        \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      4. metadata-eval83.3%

        \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      5. *-commutative83.3%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
      6. associate-*r/83.3%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
      7. associate-*l/83.4%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
      8. *-lft-identity83.4%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\color{blue}{\pi}}{b \cdot b - a \cdot a}}{2} \]
      9. difference-of-squares86.7%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
      10. associate-/r*88.5%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
    3. Simplified88.5%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. *-commutative88.5%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
      2. associate-/l/88.6%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
      3. frac-add88.5%

        \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
      4. frac-times98.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      5. +-commutative98.9%

        \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      6. *-un-lft-identity98.9%

        \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. Applied egg-rr98.9%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    7. Step-by-step derivation
      1. associate-/l*98.9%

        \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      2. +-commutative98.9%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      3. fma-define98.9%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      4. associate-*l*98.9%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    8. Applied egg-rr98.9%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    9. Taylor expanded in a around 0 99.7%

      \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
    10. Taylor expanded in a around inf 88.4%

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

    if -2.7e14 < a

    1. Initial program 77.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. *-commutative77.8%

        \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
      2. sub-neg77.8%

        \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      3. distribute-neg-frac77.8%

        \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      4. metadata-eval77.8%

        \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
      5. *-commutative77.8%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
      6. associate-*r/77.8%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
      7. associate-*l/77.9%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
      8. *-lft-identity77.9%

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

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
      10. associate-/r*87.2%

        \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
    3. Simplified87.2%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. *-commutative87.2%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
      2. associate-/l/87.2%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
      3. frac-add87.1%

        \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
      4. frac-times99.3%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      5. +-commutative99.3%

        \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      6. *-un-lft-identity99.3%

        \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. Applied egg-rr99.3%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    7. Step-by-step derivation
      1. associate-/l*99.3%

        \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
      2. +-commutative99.3%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      3. fma-define99.3%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
      4. associate-*l*99.3%

        \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    8. Applied egg-rr99.3%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
    9. Taylor expanded in a around 0 99.6%

      \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
    10. Taylor expanded in a around 0 66.4%

      \[\leadsto \color{blue}{\frac{\pi}{b}} \cdot \frac{0.5}{a \cdot b} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -2.7 \cdot 10^{+14}:\\ \;\;\;\;\frac{0.5}{a \cdot b} \cdot \frac{\pi}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{a \cdot b} \cdot \frac{\pi}{b}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.6% accurate, 1.9× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{\pi}{a + b} \cdot \frac{0.5}{a \cdot b} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* (/ PI (+ a b)) (/ 0.5 (* a b))))
assert(a < b);
double code(double a, double b) {
	return (((double) M_PI) / (a + b)) * (0.5 / (a * b));
}
assert a < b;
public static double code(double a, double b) {
	return (Math.PI / (a + b)) * (0.5 / (a * b));
}
[a, b] = sort([a, b])
def code(a, b):
	return (math.pi / (a + b)) * (0.5 / (a * b))
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(pi / Float64(a + b)) * Float64(0.5 / Float64(a * b)))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = (pi / (a + b)) * (0.5 / (a * b));
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(Pi / N[(a + b), $MachinePrecision]), $MachinePrecision] * N[(0.5 / N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{\pi}{a + b} \cdot \frac{0.5}{a \cdot b}
\end{array}
Derivation
  1. Initial program 79.1%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. *-commutative79.1%

      \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
    2. sub-neg79.1%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    3. distribute-neg-frac79.1%

      \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    4. metadata-eval79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    5. *-commutative79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
    6. associate-*r/79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
    7. associate-*l/79.2%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
    8. *-lft-identity79.2%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\color{blue}{\pi}}{b \cdot b - a \cdot a}}{2} \]
    9. difference-of-squares87.0%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
    10. associate-/r*87.5%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
  3. Simplified87.5%

    \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. *-commutative87.5%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
    2. associate-/l/87.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
    3. frac-add87.5%

      \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
    4. frac-times99.2%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    5. +-commutative99.2%

      \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. *-un-lft-identity99.2%

      \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
  6. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
  7. Step-by-step derivation
    1. associate-/l*99.2%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    2. +-commutative99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    3. fma-define99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    4. associate-*l*99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
  8. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
  9. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
  10. Final simplification99.6%

    \[\leadsto \frac{\pi}{a + b} \cdot \frac{0.5}{a \cdot b} \]
  11. Add Preprocessing

Alternative 4: 63.4% accurate, 2.3× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{0.5}{a \cdot b} \cdot \frac{\pi}{a} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* (/ 0.5 (* a b)) (/ PI a)))
assert(a < b);
double code(double a, double b) {
	return (0.5 / (a * b)) * (((double) M_PI) / a);
}
assert a < b;
public static double code(double a, double b) {
	return (0.5 / (a * b)) * (Math.PI / a);
}
[a, b] = sort([a, b])
def code(a, b):
	return (0.5 / (a * b)) * (math.pi / a)
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(0.5 / Float64(a * b)) * Float64(pi / a))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = (0.5 / (a * b)) * (pi / a);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(0.5 / N[(a * b), $MachinePrecision]), $MachinePrecision] * N[(Pi / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{0.5}{a \cdot b} \cdot \frac{\pi}{a}
\end{array}
Derivation
  1. Initial program 79.1%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. *-commutative79.1%

      \[\leadsto \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \]
    2. sub-neg79.1%

      \[\leadsto \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)} \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    3. distribute-neg-frac79.1%

      \[\leadsto \left(\frac{1}{a} + \color{blue}{\frac{-1}{b}}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    4. metadata-eval79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{\color{blue}{-1}}{b}\right) \cdot \left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \]
    5. *-commutative79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\left(\frac{1}{b \cdot b - a \cdot a} \cdot \frac{\pi}{2}\right)} \]
    6. associate-*r/79.1%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \color{blue}{\frac{\frac{1}{b \cdot b - a \cdot a} \cdot \pi}{2}} \]
    7. associate-*l/79.2%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{1 \cdot \pi}{b \cdot b - a \cdot a}}}{2} \]
    8. *-lft-identity79.2%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\color{blue}{\pi}}{b \cdot b - a \cdot a}}{2} \]
    9. difference-of-squares87.0%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}}}{2} \]
    10. associate-/r*87.5%

      \[\leadsto \left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\color{blue}{\frac{\frac{\pi}{b + a}}{b - a}}}{2} \]
  3. Simplified87.5%

    \[\leadsto \color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\frac{\frac{\pi}{b + a}}{b - a}}{2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. *-commutative87.5%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{b + a}}{b - a}}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)} \]
    2. associate-/l/87.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right) \]
    3. frac-add87.5%

      \[\leadsto \frac{\frac{\pi}{b + a}}{2 \cdot \left(b - a\right)} \cdot \color{blue}{\frac{1 \cdot b + a \cdot -1}{a \cdot b}} \]
    4. frac-times99.2%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b + a} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    5. +-commutative99.2%

      \[\leadsto \frac{\frac{\pi}{\color{blue}{a + b}} \cdot \left(1 \cdot b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    6. *-un-lft-identity99.2%

      \[\leadsto \frac{\frac{\pi}{a + b} \cdot \left(\color{blue}{b} + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
  6. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\frac{\pi}{a + b} \cdot \left(b + a \cdot -1\right)}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
  7. Step-by-step derivation
    1. associate-/l*99.2%

      \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{b + a \cdot -1}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)}} \]
    2. +-commutative99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{a \cdot -1 + b}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    3. fma-define99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\color{blue}{\mathsf{fma}\left(a, -1, b\right)}}{\left(2 \cdot \left(b - a\right)\right) \cdot \left(a \cdot b\right)} \]
    4. associate-*l*99.2%

      \[\leadsto \frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{\color{blue}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
  8. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\pi}{a + b} \cdot \frac{\mathsf{fma}\left(a, -1, b\right)}{2 \cdot \left(\left(b - a\right) \cdot \left(a \cdot b\right)\right)}} \]
  9. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\pi}{a + b} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
  10. Taylor expanded in a around inf 64.4%

    \[\leadsto \color{blue}{\frac{\pi}{a}} \cdot \frac{0.5}{a \cdot b} \]
  11. Final simplification64.4%

    \[\leadsto \frac{0.5}{a \cdot b} \cdot \frac{\pi}{a} \]
  12. Add Preprocessing

Reproduce

?
herbie shell --seed 2024048 
(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))))