NMSE Section 6.1 mentioned, B

Percentage Accurate: 79.2% → 99.7%
Time: 12.3s
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: 79.2% 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, 1.9× speedup?

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

\\
\frac{\frac{0.5 \cdot \pi}{a + b}}{a \cdot b}
\end{array}
Derivation
  1. Initial program 80.7%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv80.7%

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

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*88.8%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv88.8%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval88.8%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr88.8%

    \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Step-by-step derivation
    1. associate-*l/99.3%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    2. associate-/l*99.2%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a} \]
  6. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
  7. Step-by-step derivation
    1. associate-/l*99.3%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    2. +-commutative99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
    3. sub-neg99.3%

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

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
    5. metadata-eval99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b - a} \]
  8. Simplified99.3%

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

    \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  10. Step-by-step derivation
    1. un-div-inv99.7%

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

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{a + b}}}{a \cdot b} \]
    3. +-commutative99.7%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b + a}}}{a \cdot b} \]
    4. clear-num99.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{b + a}}}} \]
    5. +-commutative99.1%

      \[\leadsto \frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{\color{blue}{a + b}}}} \]
    6. associate-*r/99.1%

      \[\leadsto \frac{1}{\frac{a \cdot b}{\color{blue}{\pi \cdot \frac{0.5}{a + b}}}} \]
  11. Applied egg-rr99.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\pi \cdot \frac{0.5}{a + b}}}} \]
  12. Step-by-step derivation
    1. associate-/r/99.6%

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

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

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

      \[\leadsto \frac{\color{blue}{--1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
    5. neg-mul-199.7%

      \[\leadsto \frac{-\color{blue}{\left(-\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
    6. remove-double-neg99.7%

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

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{a + b}}}{a \cdot b} \]
    8. *-commutative99.7%

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

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

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

Alternative 2: 96.3% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 4.5 \cdot 10^{+78}:\\ \;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \frac{\pi}{b}\right) \cdot \frac{\frac{1}{a}}{b}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 4.5e+78)
   (* PI (/ 0.5 (* a (* b (+ a b)))))
   (* (* 0.5 (/ PI b)) (/ (/ 1.0 a) b))))
double code(double a, double b) {
	double tmp;
	if (b <= 4.5e+78) {
		tmp = ((double) M_PI) * (0.5 / (a * (b * (a + b))));
	} else {
		tmp = (0.5 * (((double) M_PI) / b)) * ((1.0 / a) / b);
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 4.5e+78) {
		tmp = Math.PI * (0.5 / (a * (b * (a + b))));
	} else {
		tmp = (0.5 * (Math.PI / b)) * ((1.0 / a) / b);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 4.5e+78:
		tmp = math.pi * (0.5 / (a * (b * (a + b))))
	else:
		tmp = (0.5 * (math.pi / b)) * ((1.0 / a) / b)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 4.5e+78)
		tmp = Float64(pi * Float64(0.5 / Float64(a * Float64(b * Float64(a + b)))));
	else
		tmp = Float64(Float64(0.5 * Float64(pi / b)) * Float64(Float64(1.0 / a) / b));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 4.5e+78)
		tmp = pi * (0.5 / (a * (b * (a + b))));
	else
		tmp = (0.5 * (pi / b)) * ((1.0 / a) / b);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 4.5e+78], N[(Pi * N[(0.5 / N[(a * N[(b * N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[(Pi / b), $MachinePrecision]), $MachinePrecision] * N[(N[(1.0 / a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 4.5 \cdot 10^{+78}:\\
\;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\left(0.5 \cdot \frac{\pi}{b}\right) \cdot \frac{\frac{1}{a}}{b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 4.4999999999999999e78

    1. Initial program 83.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv83.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares89.7%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*90.6%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv90.6%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval90.6%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr90.6%

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

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

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

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    7. Step-by-step derivation
      1. associate-/l*99.6%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
      2. +-commutative99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
      3. sub-neg99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b - a} \]
      4. distribute-neg-frac99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
      5. metadata-eval99.6%

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

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}} \]
    9. Taylor expanded in a around 0 99.5%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    10. Step-by-step derivation
      1. un-div-inv99.6%

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

        \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{a + b}}}{a \cdot b} \]
      3. +-commutative99.7%

        \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b + a}}}{a \cdot b} \]
      4. clear-num98.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{b + a}}}} \]
      5. +-commutative98.9%

        \[\leadsto \frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{\color{blue}{a + b}}}} \]
      6. associate-*r/98.9%

        \[\leadsto \frac{1}{\frac{a \cdot b}{\color{blue}{\pi \cdot \frac{0.5}{a + b}}}} \]
    11. Applied egg-rr98.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\pi \cdot \frac{0.5}{a + b}}}} \]
    12. Step-by-step derivation
      1. associate-/r/99.5%

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

        \[\leadsto \color{blue}{\frac{1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}{a \cdot b}} \]
      3. metadata-eval99.6%

        \[\leadsto \frac{\color{blue}{\left(--1\right)} \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}{a \cdot b} \]
      4. distribute-lft-neg-in99.6%

        \[\leadsto \frac{\color{blue}{--1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
      5. neg-mul-199.6%

        \[\leadsto \frac{-\color{blue}{\left(-\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
      6. remove-double-neg99.6%

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

        \[\leadsto \color{blue}{\pi \cdot \frac{\frac{0.5}{a + b}}{a \cdot b}} \]
      8. associate-/r*99.0%

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

        \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{\left(a \cdot b\right) \cdot \left(a + b\right)}} \]
      10. associate-*l*94.5%

        \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
    13. Simplified94.5%

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

    if 4.4999999999999999e78 < b

    1. Initial program 67.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv67.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares81.6%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*81.6%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv81.6%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval81.6%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr81.6%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. associate-*l/97.8%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
      2. associate-/l*97.7%

        \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a} \]
    6. Applied egg-rr97.7%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    7. Step-by-step derivation
      1. associate-/l*97.8%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
      2. +-commutative97.8%

        \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
      3. sub-neg97.8%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b - a} \]
      4. distribute-neg-frac97.8%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
      5. metadata-eval97.8%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b - a} \]
    8. Simplified97.8%

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

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    10. Step-by-step derivation
      1. associate-/r*97.8%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    11. Simplified97.8%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{\frac{1}{a}}{b}} \]
    12. Taylor expanded in a around 0 97.9%

      \[\leadsto \color{blue}{\left(0.5 \cdot \frac{\pi}{b}\right)} \cdot \frac{\frac{1}{a}}{b} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 4.5 \cdot 10^{+78}:\\ \;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \frac{\pi}{b}\right) \cdot \frac{\frac{1}{a}}{b}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 96.3% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2.9 \cdot 10^{+77}:\\ \;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 \cdot \frac{\pi}{a \cdot b}}{b - a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 2.9e+77)
   (* PI (/ 0.5 (* a (* b (+ a b)))))
   (/ (* 0.5 (/ PI (* a b))) (- b a))))
double code(double a, double b) {
	double tmp;
	if (b <= 2.9e+77) {
		tmp = ((double) M_PI) * (0.5 / (a * (b * (a + b))));
	} else {
		tmp = (0.5 * (((double) M_PI) / (a * b))) / (b - a);
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 2.9e+77) {
		tmp = Math.PI * (0.5 / (a * (b * (a + b))));
	} else {
		tmp = (0.5 * (Math.PI / (a * b))) / (b - a);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 2.9e+77:
		tmp = math.pi * (0.5 / (a * (b * (a + b))))
	else:
		tmp = (0.5 * (math.pi / (a * b))) / (b - a)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 2.9e+77)
		tmp = Float64(pi * Float64(0.5 / Float64(a * Float64(b * Float64(a + b)))));
	else
		tmp = Float64(Float64(0.5 * Float64(pi / Float64(a * b))) / Float64(b - a));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 2.9e+77)
		tmp = pi * (0.5 / (a * (b * (a + b))));
	else
		tmp = (0.5 * (pi / (a * b))) / (b - a);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 2.9e+77], N[(Pi * N[(0.5 / N[(a * N[(b * N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[(Pi / N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.9 \cdot 10^{+77}:\\
\;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 2.9000000000000002e77

    1. Initial program 83.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv83.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares89.7%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*90.6%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv90.6%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval90.6%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr90.6%

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

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

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

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    7. Step-by-step derivation
      1. associate-/l*99.6%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
      2. +-commutative99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
      3. sub-neg99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b - a} \]
      4. distribute-neg-frac99.6%

        \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
      5. metadata-eval99.6%

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

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b - a}} \]
    9. Taylor expanded in a around 0 99.5%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
    10. Step-by-step derivation
      1. un-div-inv99.6%

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

        \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{a + b}}}{a \cdot b} \]
      3. +-commutative99.7%

        \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b + a}}}{a \cdot b} \]
      4. clear-num98.9%

        \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{b + a}}}} \]
      5. +-commutative98.9%

        \[\leadsto \frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{\color{blue}{a + b}}}} \]
      6. associate-*r/98.9%

        \[\leadsto \frac{1}{\frac{a \cdot b}{\color{blue}{\pi \cdot \frac{0.5}{a + b}}}} \]
    11. Applied egg-rr98.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\pi \cdot \frac{0.5}{a + b}}}} \]
    12. Step-by-step derivation
      1. associate-/r/99.5%

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

        \[\leadsto \color{blue}{\frac{1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}{a \cdot b}} \]
      3. metadata-eval99.6%

        \[\leadsto \frac{\color{blue}{\left(--1\right)} \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}{a \cdot b} \]
      4. distribute-lft-neg-in99.6%

        \[\leadsto \frac{\color{blue}{--1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
      5. neg-mul-199.6%

        \[\leadsto \frac{-\color{blue}{\left(-\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
      6. remove-double-neg99.6%

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

        \[\leadsto \color{blue}{\pi \cdot \frac{\frac{0.5}{a + b}}{a \cdot b}} \]
      8. associate-/r*99.0%

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

        \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{\left(a \cdot b\right) \cdot \left(a + b\right)}} \]
      10. associate-*l*94.5%

        \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
    13. Simplified94.5%

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

    if 2.9000000000000002e77 < b

    1. Initial program 67.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv67.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares81.6%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*81.6%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv81.6%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval81.6%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr81.6%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. associate-*l/97.8%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
      2. associate-/l*97.7%

        \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a} \]
    6. Applied egg-rr97.7%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    7. Taylor expanded in b around inf 99.8%

      \[\leadsto \frac{\color{blue}{0.5 \cdot \frac{\pi}{a \cdot b}}}{b - a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 2.9 \cdot 10^{+77}:\\ \;\;\;\;\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 \cdot \frac{\pi}{a \cdot b}}{b - a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 93.3% accurate, 1.9× speedup?

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

\\
\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}
\end{array}
Derivation
  1. Initial program 80.7%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv80.7%

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

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*88.8%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv88.8%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval88.8%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr88.8%

    \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Step-by-step derivation
    1. associate-*l/99.3%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    2. associate-/l*99.2%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a} \]
  6. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
  7. Step-by-step derivation
    1. associate-/l*99.3%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    2. +-commutative99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
    3. sub-neg99.3%

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

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
    5. metadata-eval99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b - a} \]
  8. Simplified99.3%

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

    \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  10. Step-by-step derivation
    1. un-div-inv99.7%

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

      \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{a + b}}}{a \cdot b} \]
    3. +-commutative99.7%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b + a}}}{a \cdot b} \]
    4. clear-num99.1%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{b + a}}}} \]
    5. +-commutative99.1%

      \[\leadsto \frac{1}{\frac{a \cdot b}{\frac{\pi \cdot 0.5}{\color{blue}{a + b}}}} \]
    6. associate-*r/99.1%

      \[\leadsto \frac{1}{\frac{a \cdot b}{\color{blue}{\pi \cdot \frac{0.5}{a + b}}}} \]
  11. Applied egg-rr99.1%

    \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot b}{\pi \cdot \frac{0.5}{a + b}}}} \]
  12. Step-by-step derivation
    1. associate-/r/99.6%

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

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

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

      \[\leadsto \frac{\color{blue}{--1 \cdot \left(\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
    5. neg-mul-199.7%

      \[\leadsto \frac{-\color{blue}{\left(-\pi \cdot \frac{0.5}{a + b}\right)}}{a \cdot b} \]
    6. remove-double-neg99.7%

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

      \[\leadsto \color{blue}{\pi \cdot \frac{\frac{0.5}{a + b}}{a \cdot b}} \]
    8. associate-/r*99.1%

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

      \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{\left(a \cdot b\right) \cdot \left(a + b\right)}} \]
    10. associate-*l*91.9%

      \[\leadsto \pi \cdot \frac{0.5}{\color{blue}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
  13. Simplified91.9%

    \[\leadsto \color{blue}{\pi \cdot \frac{0.5}{a \cdot \left(b \cdot \left(a + b\right)\right)}} \]
  14. Final simplification91.9%

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

Alternative 5: 99.0% accurate, 1.9× speedup?

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

\\
\frac{0.5 \cdot \pi}{\left(a + b\right) \cdot \left(a \cdot b\right)}
\end{array}
Derivation
  1. Initial program 80.7%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv80.7%

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

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*88.8%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv88.8%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval88.8%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr88.8%

    \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Step-by-step derivation
    1. associate-*l/99.3%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    2. associate-/l*99.2%

      \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a} \]
  6. Applied egg-rr99.2%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
  7. Step-by-step derivation
    1. associate-/l*99.3%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{0.5}{b + a}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a}} \]
    2. +-commutative99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{\color{blue}{a + b}}\right) \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
    3. sub-neg99.3%

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

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
    5. metadata-eval99.3%

      \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b - a} \]
  8. Simplified99.3%

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

    \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  10. Step-by-step derivation
    1. *-commutative99.6%

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

      \[\leadsto \frac{1}{a \cdot b} \cdot \color{blue}{\frac{\pi \cdot 0.5}{a + b}} \]
    3. +-commutative99.6%

      \[\leadsto \frac{1}{a \cdot b} \cdot \frac{\pi \cdot 0.5}{\color{blue}{b + a}} \]
    4. frac-times99.2%

      \[\leadsto \color{blue}{\frac{1 \cdot \left(\pi \cdot 0.5\right)}{\left(a \cdot b\right) \cdot \left(b + a\right)}} \]
    5. *-un-lft-identity99.2%

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

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

    \[\leadsto \color{blue}{\frac{\pi \cdot 0.5}{\left(a \cdot b\right) \cdot \left(a + b\right)}} \]
  12. Final simplification99.2%

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

Reproduce

?
herbie shell --seed 2024059 
(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))))