NMSE Section 6.1 mentioned, B

Percentage Accurate: 79.3% → 99.7%
Time: 10.1s
Alternatives: 5
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 5 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: 79.3% 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, 1.9× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{\frac{\frac{\pi}{b}}{2 \cdot a}}{b + a} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (/ (/ (/ PI b) (* 2.0 a)) (+ b a)))
assert(a < b);
double code(double a, double b) {
	return ((((double) M_PI) / b) / (2.0 * a)) / (b + a);
}
assert a < b;
public static double code(double a, double b) {
	return ((Math.PI / b) / (2.0 * a)) / (b + a);
}
[a, b] = sort([a, b])
def code(a, b):
	return ((math.pi / b) / (2.0 * a)) / (b + a)
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(Float64(pi / b) / Float64(2.0 * a)) / Float64(b + a))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = ((pi / b) / (2.0 * a)) / (b + a);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(N[(Pi / b), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision] / N[(b + a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{\frac{\frac{\pi}{b}}{2 \cdot a}}{b + a}
\end{array}
Derivation
  1. Initial program 80.2%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. associate-*l/80.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    3. *-lft-identity80.2%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    4. difference-of-squares90.4%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} - \frac{1}{b}}{b - a}}{b + a}} \]
    6. sub-neg99.6%

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

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a}}{b + a} \]
    8. metadata-eval99.6%

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

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

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
    3. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
  6. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
  7. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1}{a \cdot b}}}{b + a} \]
  8. Step-by-step derivation
    1. associate-/r*99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}}}{b + a} \]
    2. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{--1}}{a}}{b}}{b + a} \]
    3. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{-\frac{-1}{a}}}{b}}{b + a} \]
    4. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{\frac{-1}{a}}{b}\right)}}{b + a} \]
    5. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{1 \cdot \frac{-1}{a}}}{b}\right)}{b + a} \]
    6. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{b} \cdot \frac{-1}{a}}\right)}{b + a} \]
    7. distribute-lft-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(\left(-\frac{1}{b}\right) \cdot \frac{-1}{a}\right)}}{b + a} \]
    8. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\color{blue}{\frac{-1}{b}} \cdot \frac{-1}{a}\right)}{b + a} \]
    9. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{\color{blue}{-1}}{b} \cdot \frac{-1}{a}\right)}{b + a} \]
    10. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \frac{\color{blue}{-1}}{a}\right)}{b + a} \]
    11. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \color{blue}{\left(-\frac{1}{a}\right)}\right)}{b + a} \]
    12. distribute-rgt-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{-1}{b} \cdot \frac{1}{a}\right)}}{b + a} \]
    13. *-commutative99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{a} \cdot \frac{-1}{b}}\right)}{b + a} \]
    14. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1 \cdot \frac{-1}{b}}{a}}\right)}{b + a} \]
    15. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{\frac{-1}{b}}}{a}\right)}{b + a} \]
    16. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{-\frac{-1}{b}}{a}}}{b + a} \]
    17. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{--1}{b}}}{a}}{b + a} \]
    18. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{1}}{b}}{a}}{b + a} \]
  9. Simplified99.7%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{b}}{a}}}{b + a} \]
  10. Step-by-step derivation
    1. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    3. frac-times99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot \frac{1}{b}}{2 \cdot a}}}{b + a} \]
    4. div-inv99.7%

      \[\leadsto \frac{\frac{\color{blue}{\frac{\pi}{b}}}{2 \cdot a}}{b + a} \]
  11. Applied egg-rr99.7%

    \[\leadsto \frac{\color{blue}{\frac{\frac{\pi}{b}}{2 \cdot a}}}{b + a} \]
  12. Final simplification99.7%

    \[\leadsto \frac{\frac{\frac{\pi}{b}}{2 \cdot a}}{b + a} \]
  13. Add Preprocessing

Alternative 2: 98.9% accurate, 1.9× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \pi \cdot \frac{0.5}{\left(b + a\right) \cdot \left(b \cdot a\right)} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* PI (/ 0.5 (* (+ b a) (* b a)))))
assert(a < b);
double code(double a, double b) {
	return ((double) M_PI) * (0.5 / ((b + a) * (b * a)));
}
assert a < b;
public static double code(double a, double b) {
	return Math.PI * (0.5 / ((b + a) * (b * a)));
}
[a, b] = sort([a, b])
def code(a, b):
	return math.pi * (0.5 / ((b + a) * (b * a)))
a, b = sort([a, b])
function code(a, b)
	return Float64(pi * Float64(0.5 / Float64(Float64(b + a) * Float64(b * a))))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = pi * (0.5 / ((b + a) * (b * a)));
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(Pi * N[(0.5 / N[(N[(b + a), $MachinePrecision] * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\pi \cdot \frac{0.5}{\left(b + a\right) \cdot \left(b \cdot a\right)}
\end{array}
Derivation
  1. Initial program 80.2%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. associate-*l/80.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    3. *-lft-identity80.2%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    4. difference-of-squares90.4%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} - \frac{1}{b}}{b - a}}{b + a}} \]
    6. sub-neg99.6%

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

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a}}{b + a} \]
    8. metadata-eval99.6%

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

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

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
    3. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
  6. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
  7. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1}{a \cdot b}}}{b + a} \]
  8. Step-by-step derivation
    1. associate-/r*99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}}}{b + a} \]
    2. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{--1}}{a}}{b}}{b + a} \]
    3. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{-\frac{-1}{a}}}{b}}{b + a} \]
    4. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{\frac{-1}{a}}{b}\right)}}{b + a} \]
    5. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{1 \cdot \frac{-1}{a}}}{b}\right)}{b + a} \]
    6. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{b} \cdot \frac{-1}{a}}\right)}{b + a} \]
    7. distribute-lft-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(\left(-\frac{1}{b}\right) \cdot \frac{-1}{a}\right)}}{b + a} \]
    8. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\color{blue}{\frac{-1}{b}} \cdot \frac{-1}{a}\right)}{b + a} \]
    9. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{\color{blue}{-1}}{b} \cdot \frac{-1}{a}\right)}{b + a} \]
    10. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \frac{\color{blue}{-1}}{a}\right)}{b + a} \]
    11. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \color{blue}{\left(-\frac{1}{a}\right)}\right)}{b + a} \]
    12. distribute-rgt-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{-1}{b} \cdot \frac{1}{a}\right)}}{b + a} \]
    13. *-commutative99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{a} \cdot \frac{-1}{b}}\right)}{b + a} \]
    14. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1 \cdot \frac{-1}{b}}{a}}\right)}{b + a} \]
    15. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{\frac{-1}{b}}}{a}\right)}{b + a} \]
    16. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{-\frac{-1}{b}}{a}}}{b + a} \]
    17. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{--1}{b}}}{a}}{b + a} \]
    18. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{1}}{b}}{a}}{b + a} \]
  9. Simplified99.7%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{b}}{a}}}{b + a} \]
  10. Step-by-step derivation
    1. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    3. frac-times99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot \frac{1}{b}}{2 \cdot a}}}{b + a} \]
    4. div-inv99.7%

      \[\leadsto \frac{\frac{\color{blue}{\frac{\pi}{b}}}{2 \cdot a}}{b + a} \]
  11. Applied egg-rr99.7%

    \[\leadsto \frac{\color{blue}{\frac{\frac{\pi}{b}}{2 \cdot a}}}{b + a} \]
  12. Step-by-step derivation
    1. expm1-log1p-u80.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\frac{\frac{\pi}{b}}{2 \cdot a}}{b + a}\right)\right)} \]
    2. expm1-udef57.8%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{\frac{\frac{\pi}{b}}{2 \cdot a}}{b + a}\right)} - 1} \]
    3. associate-/l/57.8%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\frac{\frac{\pi}{b}}{\left(b + a\right) \cdot \left(2 \cdot a\right)}}\right)} - 1 \]
  13. Applied egg-rr57.8%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{\frac{\pi}{b}}{\left(b + a\right) \cdot \left(2 \cdot a\right)}\right)} - 1} \]
  14. Step-by-step derivation
    1. expm1-def74.6%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{\frac{\pi}{b}}{\left(b + a\right) \cdot \left(2 \cdot a\right)}\right)\right)} \]
    2. expm1-log1p94.2%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b}}{\left(b + a\right) \cdot \left(2 \cdot a\right)}} \]
    3. *-lft-identity94.2%

      \[\leadsto \frac{\color{blue}{1 \cdot \frac{\pi}{b}}}{\left(b + a\right) \cdot \left(2 \cdot a\right)} \]
    4. associate-*l/94.2%

      \[\leadsto \color{blue}{\frac{1}{\left(b + a\right) \cdot \left(2 \cdot a\right)} \cdot \frac{\pi}{b}} \]
    5. associate-/l/95.0%

      \[\leadsto \color{blue}{\frac{\frac{1}{2 \cdot a}}{b + a}} \cdot \frac{\pi}{b} \]
    6. *-commutative95.0%

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

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

      \[\leadsto \frac{\frac{\pi}{b} \cdot \color{blue}{\frac{\frac{1}{2}}{a}}}{b + a} \]
    9. metadata-eval99.7%

      \[\leadsto \frac{\frac{\pi}{b} \cdot \frac{\color{blue}{0.5}}{a}}{b + a} \]
    10. times-frac99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{b \cdot a}}}{b + a} \]
    11. associate-/r*99.7%

      \[\leadsto \frac{\color{blue}{\frac{\frac{\pi \cdot 0.5}{b}}{a}}}{b + a} \]
    12. associate-*r/99.7%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{0.5}{b}}}{a}}{b + a} \]
    13. associate-/r*94.2%

      \[\leadsto \color{blue}{\frac{\pi \cdot \frac{0.5}{b}}{a \cdot \left(b + a\right)}} \]
    14. times-frac95.9%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{\frac{0.5}{b}}{b + a}} \]
    15. associate-/r*95.9%

      \[\leadsto \frac{\pi}{a} \cdot \color{blue}{\frac{0.5}{b \cdot \left(b + a\right)}} \]
    16. associate-*l/95.8%

      \[\leadsto \color{blue}{\frac{\pi \cdot \frac{0.5}{b \cdot \left(b + a\right)}}{a}} \]
    17. associate-*r/95.8%

      \[\leadsto \color{blue}{\pi \cdot \frac{\frac{0.5}{b \cdot \left(b + a\right)}}{a}} \]
    18. associate-/l/95.4%

      \[\leadsto \pi \cdot \color{blue}{\frac{0.5}{a \cdot \left(b \cdot \left(b + a\right)\right)}} \]
    19. remove-double-neg95.4%

      \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{-\left(-a \cdot \left(b \cdot \left(b + a\right)\right)\right)}} \]
  15. Simplified99.0%

    \[\leadsto \color{blue}{\pi \cdot \frac{0.5}{\left(a + b\right) \cdot \left(a \cdot b\right)}} \]
  16. Final simplification99.0%

    \[\leadsto \pi \cdot \frac{0.5}{\left(b + a\right) \cdot \left(b \cdot a\right)} \]
  17. Add Preprocessing

Alternative 3: 99.0% accurate, 1.9× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{0.5}{\left(b + a\right) \cdot \left(b \cdot \frac{a}{\pi}\right)} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (/ 0.5 (* (+ b a) (* b (/ a PI)))))
assert(a < b);
double code(double a, double b) {
	return 0.5 / ((b + a) * (b * (a / ((double) M_PI))));
}
assert a < b;
public static double code(double a, double b) {
	return 0.5 / ((b + a) * (b * (a / Math.PI)));
}
[a, b] = sort([a, b])
def code(a, b):
	return 0.5 / ((b + a) * (b * (a / math.pi)))
a, b = sort([a, b])
function code(a, b)
	return Float64(0.5 / Float64(Float64(b + a) * Float64(b * Float64(a / pi))))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = 0.5 / ((b + a) * (b * (a / pi)));
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(0.5 / N[(N[(b + a), $MachinePrecision] * N[(b * N[(a / Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{0.5}{\left(b + a\right) \cdot \left(b \cdot \frac{a}{\pi}\right)}
\end{array}
Derivation
  1. Initial program 80.2%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. associate-*l/80.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    3. *-lft-identity80.2%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    4. difference-of-squares90.4%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} - \frac{1}{b}}{b - a}}{b + a}} \]
    6. sub-neg99.6%

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

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a}}{b + a} \]
    8. metadata-eval99.6%

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

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

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

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}}}{b + a} \]
    2. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{--1}}{a}}{b}}{b + a} \]
    3. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{-\frac{-1}{a}}}{b}}{b + a} \]
    4. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{\frac{-1}{a}}{b}\right)}}{b + a} \]
    5. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{1 \cdot \frac{-1}{a}}}{b}\right)}{b + a} \]
    6. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{b} \cdot \frac{-1}{a}}\right)}{b + a} \]
    7. distribute-lft-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(\left(-\frac{1}{b}\right) \cdot \frac{-1}{a}\right)}}{b + a} \]
    8. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\color{blue}{\frac{-1}{b}} \cdot \frac{-1}{a}\right)}{b + a} \]
    9. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{\color{blue}{-1}}{b} \cdot \frac{-1}{a}\right)}{b + a} \]
    10. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \frac{\color{blue}{-1}}{a}\right)}{b + a} \]
    11. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \color{blue}{\left(-\frac{1}{a}\right)}\right)}{b + a} \]
    12. distribute-rgt-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{-1}{b} \cdot \frac{1}{a}\right)}}{b + a} \]
    13. *-commutative99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{a} \cdot \frac{-1}{b}}\right)}{b + a} \]
    14. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1 \cdot \frac{-1}{b}}{a}}\right)}{b + a} \]
    15. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{\frac{-1}{b}}}{a}\right)}{b + a} \]
    16. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{-\frac{-1}{b}}{a}}}{b + a} \]
    17. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{--1}{b}}}{a}}{b + a} \]
    18. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{1}}{b}}{a}}{b + a} \]
  7. Simplified99.6%

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

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \frac{\frac{1}{b}}{a}}{b + a}} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    3. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    4. *-commutative99.7%

      \[\leadsto \frac{\color{blue}{\left(0.5 \cdot \pi\right)} \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    5. associate-/l/99.6%

      \[\leadsto \frac{\left(0.5 \cdot \pi\right) \cdot \color{blue}{\frac{1}{a \cdot b}}}{b + a} \]
    6. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\frac{0.5 \cdot \pi}{a \cdot b}}}{b + a} \]
    7. div-inv99.6%

      \[\leadsto \color{blue}{\frac{0.5 \cdot \pi}{a \cdot b} \cdot \frac{1}{b + a}} \]
    8. associate-/l*99.5%

      \[\leadsto \color{blue}{\frac{0.5}{\frac{a \cdot b}{\pi}}} \cdot \frac{1}{b + a} \]
    9. frac-times99.0%

      \[\leadsto \color{blue}{\frac{0.5 \cdot 1}{\frac{a \cdot b}{\pi} \cdot \left(b + a\right)}} \]
    10. metadata-eval99.0%

      \[\leadsto \frac{\color{blue}{0.5}}{\frac{a \cdot b}{\pi} \cdot \left(b + a\right)} \]
    11. *-commutative99.0%

      \[\leadsto \frac{0.5}{\frac{\color{blue}{b \cdot a}}{\pi} \cdot \left(b + a\right)} \]
    12. *-un-lft-identity99.0%

      \[\leadsto \frac{0.5}{\frac{b \cdot a}{\color{blue}{1 \cdot \pi}} \cdot \left(b + a\right)} \]
    13. times-frac99.0%

      \[\leadsto \frac{0.5}{\color{blue}{\left(\frac{b}{1} \cdot \frac{a}{\pi}\right)} \cdot \left(b + a\right)} \]
    14. /-rgt-identity99.0%

      \[\leadsto \frac{0.5}{\left(\color{blue}{b} \cdot \frac{a}{\pi}\right) \cdot \left(b + a\right)} \]
  9. Applied egg-rr99.0%

    \[\leadsto \color{blue}{\frac{0.5}{\left(b \cdot \frac{a}{\pi}\right) \cdot \left(b + a\right)}} \]
  10. Final simplification99.0%

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

Alternative 4: 99.6% accurate, 1.9× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{\frac{\pi}{a} \cdot \frac{0.5}{b}}{b + a} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (/ (* (/ PI a) (/ 0.5 b)) (+ b a)))
assert(a < b);
double code(double a, double b) {
	return ((((double) M_PI) / a) * (0.5 / b)) / (b + a);
}
assert a < b;
public static double code(double a, double b) {
	return ((Math.PI / a) * (0.5 / b)) / (b + a);
}
[a, b] = sort([a, b])
def code(a, b):
	return ((math.pi / a) * (0.5 / b)) / (b + a)
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(Float64(pi / a) * Float64(0.5 / b)) / Float64(b + a))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = ((pi / a) * (0.5 / b)) / (b + a);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(N[(Pi / a), $MachinePrecision] * N[(0.5 / b), $MachinePrecision]), $MachinePrecision] / N[(b + a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{\frac{\pi}{a} \cdot \frac{0.5}{b}}{b + a}
\end{array}
Derivation
  1. Initial program 80.2%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. associate-*l/80.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    3. *-lft-identity80.2%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    4. difference-of-squares90.4%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} - \frac{1}{b}}{b - a}}{b + a}} \]
    6. sub-neg99.6%

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

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a}}{b + a} \]
    8. metadata-eval99.6%

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

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

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
    3. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
  6. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
  7. Taylor expanded in a around 0 99.7%

    \[\leadsto \frac{\color{blue}{0.5 \cdot \frac{\pi}{a \cdot b}}}{b + a} \]
  8. Step-by-step derivation
    1. associate-*r/99.7%

      \[\leadsto \frac{\color{blue}{\frac{0.5 \cdot \pi}{a \cdot b}}}{b + a} \]
  9. Simplified99.7%

    \[\leadsto \frac{\color{blue}{\frac{0.5 \cdot \pi}{a \cdot b}}}{b + a} \]
  10. Step-by-step derivation
    1. *-commutative99.7%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot 0.5}}{a \cdot b}}{b + a} \]
    2. times-frac99.7%

      \[\leadsto \frac{\color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b}}}{b + a} \]
  11. Applied egg-rr99.7%

    \[\leadsto \frac{\color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b}}}{b + a} \]
  12. Final simplification99.7%

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

Alternative 5: 62.8% accurate, 2.3× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \frac{\pi}{a} \cdot \frac{0.5}{b \cdot a} \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* (/ PI a) (/ 0.5 (* b a))))
assert(a < b);
double code(double a, double b) {
	return (((double) M_PI) / a) * (0.5 / (b * a));
}
assert a < b;
public static double code(double a, double b) {
	return (Math.PI / a) * (0.5 / (b * a));
}
[a, b] = sort([a, b])
def code(a, b):
	return (math.pi / a) * (0.5 / (b * a))
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(pi / a) * Float64(0.5 / Float64(b * a)))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = (pi / a) * (0.5 / (b * a));
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(Pi / a), $MachinePrecision] * N[(0.5 / N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\frac{\pi}{a} \cdot \frac{0.5}{b \cdot a}
\end{array}
Derivation
  1. Initial program 80.2%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. associate-*l/80.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    3. *-lft-identity80.2%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    4. difference-of-squares90.4%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} - \frac{1}{b}}{b - a}}{b + a}} \]
    6. sub-neg99.6%

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

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a}}{b + a} \]
    8. metadata-eval99.6%

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

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

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
    2. div-inv99.7%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
    3. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a} \]
  6. Applied egg-rr99.7%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}}{b + a}} \]
  7. Taylor expanded in a around 0 99.6%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1}{a \cdot b}}}{b + a} \]
  8. Step-by-step derivation
    1. associate-/r*99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}}}{b + a} \]
    2. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{--1}}{a}}{b}}{b + a} \]
    3. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{-\frac{-1}{a}}}{b}}{b + a} \]
    4. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{\frac{-1}{a}}{b}\right)}}{b + a} \]
    5. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{1 \cdot \frac{-1}{a}}}{b}\right)}{b + a} \]
    6. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{b} \cdot \frac{-1}{a}}\right)}{b + a} \]
    7. distribute-lft-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(\left(-\frac{1}{b}\right) \cdot \frac{-1}{a}\right)}}{b + a} \]
    8. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\color{blue}{\frac{-1}{b}} \cdot \frac{-1}{a}\right)}{b + a} \]
    9. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{\color{blue}{-1}}{b} \cdot \frac{-1}{a}\right)}{b + a} \]
    10. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \frac{\color{blue}{-1}}{a}\right)}{b + a} \]
    11. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} \cdot \color{blue}{\left(-\frac{1}{a}\right)}\right)}{b + a} \]
    12. distribute-rgt-neg-in99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\left(-\frac{-1}{b} \cdot \frac{1}{a}\right)}}{b + a} \]
    13. *-commutative99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1}{a} \cdot \frac{-1}{b}}\right)}{b + a} \]
    14. associate-*l/99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\color{blue}{\frac{1 \cdot \frac{-1}{b}}{a}}\right)}{b + a} \]
    15. *-lft-identity99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \left(-\frac{\color{blue}{\frac{-1}{b}}}{a}\right)}{b + a} \]
    16. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{-\frac{-1}{b}}{a}}}{b + a} \]
    17. distribute-neg-frac99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{--1}{b}}}{a}}{b + a} \]
    18. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{\color{blue}{1}}{b}}{a}}{b + a} \]
  9. Simplified99.7%

    \[\leadsto \frac{\left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{\frac{1}{b}}{a}}}{b + a} \]
  10. Step-by-step derivation
    1. metadata-eval99.7%

      \[\leadsto \frac{\left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{b}}{a}}{b + a} \]
    2. div-inv99.7%

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

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \frac{\frac{\frac{1}{b}}{a}}{b + a}} \]
    4. div-inv99.5%

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

      \[\leadsto \frac{\pi}{2} \cdot \left(\color{blue}{\frac{1}{a \cdot b}} \cdot \frac{1}{b + a}\right) \]
    6. frac-times99.0%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot 1}{\left(a \cdot b\right) \cdot \left(b + a\right)}} \]
    7. metadata-eval99.0%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{1}}{\left(a \cdot b\right) \cdot \left(b + a\right)} \]
    8. +-commutative99.0%

      \[\leadsto \frac{\pi}{2} \cdot \frac{1}{\left(a \cdot b\right) \cdot \color{blue}{\left(a + b\right)}} \]
    9. associate-*r*95.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{1}{\color{blue}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
    10. div-inv95.4%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
    11. div-inv95.4%

      \[\leadsto \frac{\color{blue}{\pi \cdot \frac{1}{2}}}{a \cdot \left(b \cdot \left(a + b\right)\right)} \]
    12. metadata-eval95.4%

      \[\leadsto \frac{\pi \cdot \color{blue}{0.5}}{a \cdot \left(b \cdot \left(a + b\right)\right)} \]
    13. times-frac95.9%

      \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b \cdot \left(a + b\right)}} \]
    14. +-commutative95.9%

      \[\leadsto \frac{\pi}{a} \cdot \frac{0.5}{b \cdot \color{blue}{\left(b + a\right)}} \]
  11. Applied egg-rr95.9%

    \[\leadsto \color{blue}{\frac{\pi}{a} \cdot \frac{0.5}{b \cdot \left(b + a\right)}} \]
  12. Taylor expanded in b around 0 64.8%

    \[\leadsto \frac{\pi}{a} \cdot \color{blue}{\frac{0.5}{a \cdot b}} \]
  13. Final simplification64.8%

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

Reproduce

?
herbie shell --seed 2024019 
(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))))