NMSE Section 6.1 mentioned, B

Percentage Accurate: 78.2% → 99.6%
Time: 11.4s
Alternatives: 7
Speedup: 1.6×

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 7 alternatives:

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

Initial Program: 78.2% accurate, 1.0× speedup?

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

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

Alternative 1: 99.6% accurate, 1.1× speedup?

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

\\
\frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \frac{-1}{b}}{a + b}}{b - a}
\end{array}
Derivation
  1. Initial program 76.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*76.4%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
  3. Simplified76.4%

    \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. associate-*l/76.4%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    2. sub-neg76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{1 \cdot \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)}}{b \cdot b - a \cdot a} \]
    3. *-un-lft-identity76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
    4. neg-mul-176.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{-1 \cdot \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    5. div-inv76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
    6. difference-of-squares85.0%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{-1}{b}}{b + a}}{b - a}} \]
    8. add-sqr-sqrt52.1%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}}}{b + a}}{b - a} \]
    9. sqrt-unprod77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b} \cdot \frac{-1}{b}}}}{b + a}}{b - a} \]
    10. frac-times77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{-1 \cdot -1}{b \cdot b}}}}{b + a}}{b - a} \]
    11. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1}}{b \cdot b}}}{b + a}}{b - a} \]
    12. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1 \cdot 1}}{b \cdot b}}}{b + a}}{b - a} \]
    13. frac-times77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{1}{b} \cdot \frac{1}{b}}}}{b + a}}{b - a} \]
    14. sqrt-unprod33.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}}}{b + a}}{b - a} \]
    15. add-sqr-sqrt69.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{1}{b}}}{b + a}}{b - a} \]
  6. Applied egg-rr69.3%

    \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{1}{b}}{b + a}}{b - a}} \]
  7. Step-by-step derivation
    1. +-commutative69.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\frac{1}{b} + \frac{1}{a}}}{b + a}}{b - a} \]
    2. add-sqr-sqrt33.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}} + \frac{1}{a}}{b + a}}{b - a} \]
    3. sqrt-unprod77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\sqrt{\frac{1}{b} \cdot \frac{1}{b}}} + \frac{1}{a}}{b + a}}{b - a} \]
    4. frac-times77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\sqrt{\color{blue}{\frac{1 \cdot 1}{b \cdot b}}} + \frac{1}{a}}{b + a}}{b - a} \]
    5. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\sqrt{\frac{\color{blue}{1}}{b \cdot b}} + \frac{1}{a}}{b + a}}{b - a} \]
    6. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\sqrt{\frac{\color{blue}{-1 \cdot -1}}{b \cdot b}} + \frac{1}{a}}{b + a}}{b - a} \]
    7. frac-times77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\sqrt{\color{blue}{\frac{-1}{b} \cdot \frac{-1}{b}}} + \frac{1}{a}}{b + a}}{b - a} \]
    8. sqrt-unprod52.1%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}} + \frac{1}{a}}{b + a}}{b - a} \]
    9. add-sqr-sqrt99.6%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\frac{-1}{b}} + \frac{1}{a}}{b + a}}{b - a} \]
    10. div-inv99.6%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{-1 \cdot \frac{1}{b}} + \frac{1}{a}}{b + a}}{b - a} \]
    11. fma-define99.6%

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

    \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\mathsf{fma}\left(-1, \frac{1}{b}, \frac{1}{a}\right)}}{b + a}}{b - a} \]
  9. Step-by-step derivation
    1. fma-undefine99.6%

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

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

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

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

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

    \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\color{blue}{\frac{1}{a} + \frac{-1}{b}}}{b + a}}{b - a} \]
  11. Final simplification99.6%

    \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \frac{-1}{b}}{a + b}}{b - a} \]
  12. Add Preprocessing

Alternative 2: 99.6% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{-1}{a} + \frac{1}{b}}{a - b} \end{array} \]
(FPCore (a b)
 :precision binary64
 (* (* PI (/ 0.5 (+ a b))) (/ (+ (/ -1.0 a) (/ 1.0 b)) (- a b))))
double code(double a, double b) {
	return (((double) M_PI) * (0.5 / (a + b))) * (((-1.0 / a) + (1.0 / b)) / (a - b));
}
public static double code(double a, double b) {
	return (Math.PI * (0.5 / (a + b))) * (((-1.0 / a) + (1.0 / b)) / (a - b));
}
def code(a, b):
	return (math.pi * (0.5 / (a + b))) * (((-1.0 / a) + (1.0 / b)) / (a - b))
function code(a, b)
	return Float64(Float64(pi * Float64(0.5 / Float64(a + b))) * Float64(Float64(Float64(-1.0 / a) + Float64(1.0 / b)) / Float64(a - b)))
end
function tmp = code(a, b)
	tmp = (pi * (0.5 / (a + b))) * (((-1.0 / a) + (1.0 / b)) / (a - b));
end
code[a_, b_] := N[(N[(Pi * N[(0.5 / N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(-1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision] / N[(a - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{-1}{a} + \frac{1}{b}}{a - b}
\end{array}
Derivation
  1. Initial program 76.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv76.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares85.1%

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*86.4%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv86.4%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval86.4%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr86.4%

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

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b - a}} \]
    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. Final simplification99.6%

    \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{\frac{-1}{a} + \frac{1}{b}}{a - b} \]
  10. Add Preprocessing

Alternative 3: 75.5% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.02 \cdot 10^{-135}:\\ \;\;\;\;\frac{\frac{\frac{\pi \cdot 0.5}{a}}{b}}{a - b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1.02e-135)
   (/ (/ (/ (* PI 0.5) a) b) (- a b))
   (* (/ PI b) (/ (/ 0.5 a) (- b a)))))
double code(double a, double b) {
	double tmp;
	if (b <= 1.02e-135) {
		tmp = (((((double) M_PI) * 0.5) / a) / b) / (a - b);
	} else {
		tmp = (((double) M_PI) / b) * ((0.5 / a) / (b - a));
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 1.02e-135) {
		tmp = (((Math.PI * 0.5) / a) / b) / (a - b);
	} else {
		tmp = (Math.PI / b) * ((0.5 / a) / (b - a));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 1.02e-135:
		tmp = (((math.pi * 0.5) / a) / b) / (a - b)
	else:
		tmp = (math.pi / b) * ((0.5 / a) / (b - a))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 1.02e-135)
		tmp = Float64(Float64(Float64(Float64(pi * 0.5) / a) / b) / Float64(a - b));
	else
		tmp = Float64(Float64(pi / b) * Float64(Float64(0.5 / a) / Float64(b - a)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 1.02e-135)
		tmp = (((pi * 0.5) / a) / b) / (a - b);
	else
		tmp = (pi / b) * ((0.5 / a) / (b - a));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 1.02e-135], N[(N[(N[(N[(Pi * 0.5), $MachinePrecision] / a), $MachinePrecision] / b), $MachinePrecision] / N[(a - b), $MachinePrecision]), $MachinePrecision], N[(N[(Pi / b), $MachinePrecision] * N[(N[(0.5 / a), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.02 \cdot 10^{-135}:\\
\;\;\;\;\frac{\frac{\frac{\pi \cdot 0.5}{a}}{b}}{a - b}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.01999999999999994e-135

    1. Initial program 73.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv73.8%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares84.0%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*84.8%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv84.8%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval84.8%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr84.8%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Taylor expanded in b around 0 58.9%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{a}}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Taylor expanded in a around inf 61.0%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{a}}{b - a} \cdot \color{blue}{\frac{-1}{b}} \]
    7. Step-by-step derivation
      1. associate-*l/71.2%

        \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{a} \cdot \frac{-1}{b}}{b - a}} \]
      2. associate-/l*71.2%

        \[\leadsto \frac{\color{blue}{\left(\pi \cdot \frac{0.5}{a}\right)} \cdot \frac{-1}{b}}{b - a} \]
    8. Applied egg-rr71.2%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot \frac{0.5}{a}\right) \cdot \frac{-1}{b}}{b - a}} \]
    9. Step-by-step derivation
      1. associate-*r/71.2%

        \[\leadsto \frac{\color{blue}{\frac{\left(\pi \cdot \frac{0.5}{a}\right) \cdot -1}{b}}}{b - a} \]
      2. *-commutative71.2%

        \[\leadsto \frac{\frac{\color{blue}{-1 \cdot \left(\pi \cdot \frac{0.5}{a}\right)}}{b}}{b - a} \]
      3. associate-*r/71.2%

        \[\leadsto \frac{\frac{-1 \cdot \color{blue}{\frac{\pi \cdot 0.5}{a}}}{b}}{b - a} \]
      4. *-commutative71.2%

        \[\leadsto \frac{\frac{-1 \cdot \frac{\color{blue}{0.5 \cdot \pi}}{a}}{b}}{b - a} \]
      5. associate-*r/71.2%

        \[\leadsto \frac{\frac{-1 \cdot \color{blue}{\left(0.5 \cdot \frac{\pi}{a}\right)}}{b}}{b - a} \]
      6. mul-1-neg71.2%

        \[\leadsto \frac{\frac{\color{blue}{-0.5 \cdot \frac{\pi}{a}}}{b}}{b - a} \]
      7. distribute-rgt-neg-out71.2%

        \[\leadsto \frac{\frac{\color{blue}{0.5 \cdot \left(-\frac{\pi}{a}\right)}}{b}}{b - a} \]
      8. mul-1-neg71.2%

        \[\leadsto \frac{\frac{0.5 \cdot \color{blue}{\left(-1 \cdot \frac{\pi}{a}\right)}}{b}}{b - a} \]
      9. associate-*r/71.2%

        \[\leadsto \frac{\frac{0.5 \cdot \color{blue}{\frac{-1 \cdot \pi}{a}}}{b}}{b - a} \]
      10. *-commutative71.2%

        \[\leadsto \frac{\frac{0.5 \cdot \frac{\color{blue}{\pi \cdot -1}}{a}}{b}}{b - a} \]
      11. metadata-eval71.2%

        \[\leadsto \frac{\frac{0.5 \cdot \frac{\pi \cdot \color{blue}{\left(-2 - -1\right)}}{a}}{b}}{b - a} \]
      12. distribute-rgt-out--71.2%

        \[\leadsto \frac{\frac{0.5 \cdot \frac{\color{blue}{-2 \cdot \pi - -1 \cdot \pi}}{a}}{b}}{b - a} \]
      13. associate-*r/71.2%

        \[\leadsto \frac{\frac{\color{blue}{\frac{0.5 \cdot \left(-2 \cdot \pi - -1 \cdot \pi\right)}{a}}}{b}}{b - a} \]
      14. distribute-rgt-out--71.2%

        \[\leadsto \frac{\frac{\frac{0.5 \cdot \color{blue}{\left(\pi \cdot \left(-2 - -1\right)\right)}}{a}}{b}}{b - a} \]
      15. metadata-eval71.2%

        \[\leadsto \frac{\frac{\frac{0.5 \cdot \left(\pi \cdot \color{blue}{-1}\right)}{a}}{b}}{b - a} \]
      16. *-commutative71.2%

        \[\leadsto \frac{\frac{\frac{0.5 \cdot \color{blue}{\left(-1 \cdot \pi\right)}}{a}}{b}}{b - a} \]
      17. mul-1-neg71.2%

        \[\leadsto \frac{\frac{\frac{0.5 \cdot \color{blue}{\left(-\pi\right)}}{a}}{b}}{b - a} \]
    10. Simplified71.2%

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

    if 1.01999999999999994e-135 < b

    1. Initial program 81.5%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. associate-*l*81.4%

        \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    3. Simplified81.4%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. associate-*l/81.4%

        \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
      2. sub-neg81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{1 \cdot \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)}}{b \cdot b - a \cdot a} \]
      3. *-un-lft-identity81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
      4. neg-mul-181.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{-1 \cdot \frac{1}{b}}}{b \cdot b - a \cdot a} \]
      5. div-inv81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
      6. difference-of-squares87.0%

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

        \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{-1}{b}}{b + a}}{b - a}} \]
      8. add-sqr-sqrt0.0%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}}}{b + a}}{b - a} \]
      9. sqrt-unprod86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b} \cdot \frac{-1}{b}}}}{b + a}}{b - a} \]
      10. frac-times86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{-1 \cdot -1}{b \cdot b}}}}{b + a}}{b - a} \]
      11. metadata-eval86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1}}{b \cdot b}}}{b + a}}{b - a} \]
      12. metadata-eval86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1 \cdot 1}}{b \cdot b}}}{b + a}}{b - a} \]
      13. frac-times86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{1}{b} \cdot \frac{1}{b}}}}{b + a}}{b - a} \]
      14. sqrt-unprod86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}}}{b + a}}{b - a} \]
      15. add-sqr-sqrt86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{1}{b}}}{b + a}}{b - a} \]
    6. Applied egg-rr86.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{1}{b}}{b + a}}{b - a}} \]
    7. Taylor expanded in a around 0 86.1%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a \cdot b}}}{b - a} \]
    8. Step-by-step derivation
      1. div-inv86.1%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
      2. metadata-eval86.1%

        \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
      3. associate-*r/86.1%

        \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
    9. Applied egg-rr86.1%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
    10. Step-by-step derivation
      1. associate-*r/86.2%

        \[\leadsto \frac{\color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot 1}{a \cdot b}}}{b - a} \]
      2. *-commutative86.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(0.5 \cdot \pi\right)} \cdot 1}{a \cdot b}}{b - a} \]
      3. *-rgt-identity86.2%

        \[\leadsto \frac{\frac{\color{blue}{0.5 \cdot \pi}}{a \cdot b}}{b - a} \]
      4. *-commutative86.2%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot 0.5}}{a \cdot b}}{b - a} \]
      5. *-commutative86.2%

        \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b \cdot a}}}{b - a} \]
      6. times-frac86.1%

        \[\leadsto \frac{\color{blue}{\frac{\pi}{b} \cdot \frac{0.5}{a}}}{b - a} \]
    11. Simplified86.1%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b} \cdot \frac{0.5}{a}}{b - a}} \]
    12. Step-by-step derivation
      1. associate-/l*86.2%

        \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}} \]
    13. Applied egg-rr86.2%

      \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.02 \cdot 10^{-135}:\\ \;\;\;\;\frac{\frac{\frac{\pi \cdot 0.5}{a}}{b}}{a - b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 70.2% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 9.5 \cdot 10^{-137}:\\ \;\;\;\;\frac{\pi \cdot \frac{\frac{0.5}{a}}{a - b}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 9.5e-137)
   (/ (* PI (/ (/ 0.5 a) (- a b))) b)
   (* (/ PI b) (/ (/ 0.5 a) (- b a)))))
double code(double a, double b) {
	double tmp;
	if (b <= 9.5e-137) {
		tmp = (((double) M_PI) * ((0.5 / a) / (a - b))) / b;
	} else {
		tmp = (((double) M_PI) / b) * ((0.5 / a) / (b - a));
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 9.5e-137) {
		tmp = (Math.PI * ((0.5 / a) / (a - b))) / b;
	} else {
		tmp = (Math.PI / b) * ((0.5 / a) / (b - a));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 9.5e-137:
		tmp = (math.pi * ((0.5 / a) / (a - b))) / b
	else:
		tmp = (math.pi / b) * ((0.5 / a) / (b - a))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 9.5e-137)
		tmp = Float64(Float64(pi * Float64(Float64(0.5 / a) / Float64(a - b))) / b);
	else
		tmp = Float64(Float64(pi / b) * Float64(Float64(0.5 / a) / Float64(b - a)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 9.5e-137)
		tmp = (pi * ((0.5 / a) / (a - b))) / b;
	else
		tmp = (pi / b) * ((0.5 / a) / (b - a));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 9.5e-137], N[(N[(Pi * N[(N[(0.5 / a), $MachinePrecision] / N[(a - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision], N[(N[(Pi / b), $MachinePrecision] * N[(N[(0.5 / a), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 9.5 \cdot 10^{-137}:\\
\;\;\;\;\frac{\pi \cdot \frac{\frac{0.5}{a}}{a - b}}{b}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 9.5000000000000007e-137

    1. Initial program 73.8%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv73.8%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares84.0%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*84.8%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv84.8%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval84.8%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr84.8%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Taylor expanded in b around 0 58.9%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{a}}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. Taylor expanded in a around inf 61.0%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{a}}{b - a} \cdot \color{blue}{\frac{-1}{b}} \]
    7. Step-by-step derivation
      1. associate-*r/61.0%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi \cdot 0.5}{a}}{b - a} \cdot -1}{b}} \]
      2. associate-/l/60.7%

        \[\leadsto \frac{\color{blue}{\frac{\pi \cdot 0.5}{\left(b - a\right) \cdot a}} \cdot -1}{b} \]
    8. Applied egg-rr60.7%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{\left(b - a\right) \cdot a} \cdot -1}{b}} \]
    9. Step-by-step derivation
      1. *-commutative60.7%

        \[\leadsto \frac{\color{blue}{-1 \cdot \frac{\pi \cdot 0.5}{\left(b - a\right) \cdot a}}}{b} \]
      2. mul-1-neg60.7%

        \[\leadsto \frac{\color{blue}{-\frac{\pi \cdot 0.5}{\left(b - a\right) \cdot a}}}{b} \]
      3. associate-/l*60.7%

        \[\leadsto \frac{-\color{blue}{\pi \cdot \frac{0.5}{\left(b - a\right) \cdot a}}}{b} \]
      4. associate-/l/61.0%

        \[\leadsto \frac{-\pi \cdot \color{blue}{\frac{\frac{0.5}{a}}{b - a}}}{b} \]
    10. Simplified61.0%

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

    if 9.5000000000000007e-137 < b

    1. Initial program 81.5%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. associate-*l*81.4%

        \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    3. Simplified81.4%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. associate-*l/81.4%

        \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
      2. sub-neg81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{1 \cdot \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)}}{b \cdot b - a \cdot a} \]
      3. *-un-lft-identity81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
      4. neg-mul-181.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{-1 \cdot \frac{1}{b}}}{b \cdot b - a \cdot a} \]
      5. div-inv81.4%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
      6. difference-of-squares87.0%

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

        \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{-1}{b}}{b + a}}{b - a}} \]
      8. add-sqr-sqrt0.0%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}}}{b + a}}{b - a} \]
      9. sqrt-unprod86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b} \cdot \frac{-1}{b}}}}{b + a}}{b - a} \]
      10. frac-times86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{-1 \cdot -1}{b \cdot b}}}}{b + a}}{b - a} \]
      11. metadata-eval86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1}}{b \cdot b}}}{b + a}}{b - a} \]
      12. metadata-eval86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1 \cdot 1}}{b \cdot b}}}{b + a}}{b - a} \]
      13. frac-times86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{1}{b} \cdot \frac{1}{b}}}}{b + a}}{b - a} \]
      14. sqrt-unprod86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}}}{b + a}}{b - a} \]
      15. add-sqr-sqrt86.2%

        \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{1}{b}}}{b + a}}{b - a} \]
    6. Applied egg-rr86.2%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{1}{b}}{b + a}}{b - a}} \]
    7. Taylor expanded in a around 0 86.1%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a \cdot b}}}{b - a} \]
    8. Step-by-step derivation
      1. div-inv86.1%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
      2. metadata-eval86.1%

        \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
      3. associate-*r/86.1%

        \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
    9. Applied egg-rr86.1%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
    10. Step-by-step derivation
      1. associate-*r/86.2%

        \[\leadsto \frac{\color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot 1}{a \cdot b}}}{b - a} \]
      2. *-commutative86.2%

        \[\leadsto \frac{\frac{\color{blue}{\left(0.5 \cdot \pi\right)} \cdot 1}{a \cdot b}}{b - a} \]
      3. *-rgt-identity86.2%

        \[\leadsto \frac{\frac{\color{blue}{0.5 \cdot \pi}}{a \cdot b}}{b - a} \]
      4. *-commutative86.2%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot 0.5}}{a \cdot b}}{b - a} \]
      5. *-commutative86.2%

        \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b \cdot a}}}{b - a} \]
      6. times-frac86.1%

        \[\leadsto \frac{\color{blue}{\frac{\pi}{b} \cdot \frac{0.5}{a}}}{b - a} \]
    11. Simplified86.1%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{b} \cdot \frac{0.5}{a}}{b - a}} \]
    12. Step-by-step derivation
      1. associate-/l*86.2%

        \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}} \]
    13. Applied egg-rr86.2%

      \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification69.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 9.5 \cdot 10^{-137}:\\ \;\;\;\;\frac{\pi \cdot \frac{\frac{0.5}{a}}{a - b}}{b}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{1}{a \cdot b} \end{array} \]
(FPCore (a b) :precision binary64 (* (* PI (/ 0.5 (+ a b))) (/ 1.0 (* a b))))
double code(double a, double b) {
	return (((double) M_PI) * (0.5 / (a + b))) * (1.0 / (a * b));
}
public static double code(double a, double b) {
	return (Math.PI * (0.5 / (a + b))) * (1.0 / (a * b));
}
def code(a, b):
	return (math.pi * (0.5 / (a + b))) * (1.0 / (a * b))
function code(a, b)
	return Float64(Float64(pi * Float64(0.5 / Float64(a + b))) * Float64(1.0 / Float64(a * b)))
end
function tmp = code(a, b)
	tmp = (pi * (0.5 / (a + b))) * (1.0 / (a * b));
end
code[a_, b_] := N[(N[(Pi * N[(0.5 / N[(a + b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \frac{1}{a \cdot b}
\end{array}
Derivation
  1. Initial program 76.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv76.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares85.1%

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*86.4%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv86.4%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval86.4%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr86.4%

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

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

    \[\leadsto \left(\pi \cdot \frac{0.5}{a + b}\right) \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  10. Add Preprocessing

Alternative 6: 66.5% accurate, 1.9× speedup?

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

\\
\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}
\end{array}
Derivation
  1. Initial program 76.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*76.4%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
  3. Simplified76.4%

    \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. associate-*l/76.4%

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    2. sub-neg76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{1 \cdot \color{blue}{\left(\frac{1}{a} + \left(-\frac{1}{b}\right)\right)}}{b \cdot b - a \cdot a} \]
    3. *-un-lft-identity76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
    4. neg-mul-176.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{-1 \cdot \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    5. div-inv76.4%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
    6. difference-of-squares85.0%

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

      \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{-1}{b}}{b + a}}{b - a}} \]
    8. add-sqr-sqrt52.1%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}}}{b + a}}{b - a} \]
    9. sqrt-unprod77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{-1}{b} \cdot \frac{-1}{b}}}}{b + a}}{b - a} \]
    10. frac-times77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{-1 \cdot -1}{b \cdot b}}}}{b + a}}{b - a} \]
    11. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1}}{b \cdot b}}}{b + a}}{b - a} \]
    12. metadata-eval77.7%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\frac{\color{blue}{1 \cdot 1}}{b \cdot b}}}{b + a}}{b - a} \]
    13. frac-times77.8%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \sqrt{\color{blue}{\frac{1}{b} \cdot \frac{1}{b}}}}{b + a}}{b - a} \]
    14. sqrt-unprod33.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}}}{b + a}}{b - a} \]
    15. add-sqr-sqrt69.3%

      \[\leadsto \frac{\pi}{2} \cdot \frac{\frac{\frac{1}{a} + \color{blue}{\frac{1}{b}}}{b + a}}{b - a} \]
  6. Applied egg-rr69.3%

    \[\leadsto \frac{\pi}{2} \cdot \color{blue}{\frac{\frac{\frac{1}{a} + \frac{1}{b}}{b + a}}{b - a}} \]
  7. Taylor expanded in a around 0 69.3%

    \[\leadsto \frac{\pi}{2} \cdot \frac{\color{blue}{\frac{1}{a \cdot b}}}{b - a} \]
  8. Step-by-step derivation
    1. div-inv69.3%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
    2. metadata-eval69.3%

      \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \frac{\frac{1}{a \cdot b}}{b - a} \]
    3. associate-*r/69.3%

      \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
  9. Applied egg-rr69.3%

    \[\leadsto \color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot \frac{1}{a \cdot b}}{b - a}} \]
  10. Step-by-step derivation
    1. associate-*r/69.3%

      \[\leadsto \frac{\color{blue}{\frac{\left(\pi \cdot 0.5\right) \cdot 1}{a \cdot b}}}{b - a} \]
    2. *-commutative69.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(0.5 \cdot \pi\right)} \cdot 1}{a \cdot b}}{b - a} \]
    3. *-rgt-identity69.3%

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

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot 0.5}}{a \cdot b}}{b - a} \]
    5. *-commutative69.3%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{b \cdot a}}}{b - a} \]
    6. times-frac69.3%

      \[\leadsto \frac{\color{blue}{\frac{\pi}{b} \cdot \frac{0.5}{a}}}{b - a} \]
  11. Simplified69.3%

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

      \[\leadsto \color{blue}{\frac{\pi}{b} \cdot \frac{\frac{0.5}{a}}{b - a}} \]
  13. Applied egg-rr69.4%

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

Alternative 7: 31.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{-1}{b} \cdot \left(0.5 \cdot \frac{\pi}{a \cdot b}\right) \end{array} \]
(FPCore (a b) :precision binary64 (* (/ -1.0 b) (* 0.5 (/ PI (* a b)))))
double code(double a, double b) {
	return (-1.0 / b) * (0.5 * (((double) M_PI) / (a * b)));
}
public static double code(double a, double b) {
	return (-1.0 / b) * (0.5 * (Math.PI / (a * b)));
}
def code(a, b):
	return (-1.0 / b) * (0.5 * (math.pi / (a * b)))
function code(a, b)
	return Float64(Float64(-1.0 / b) * Float64(0.5 * Float64(pi / Float64(a * b))))
end
function tmp = code(a, b)
	tmp = (-1.0 / b) * (0.5 * (pi / (a * b)));
end
code[a_, b_] := N[(N[(-1.0 / b), $MachinePrecision] * N[(0.5 * N[(Pi / N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{b} \cdot \left(0.5 \cdot \frac{\pi}{a \cdot b}\right)
\end{array}
Derivation
  1. Initial program 76.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv76.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares85.1%

      \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. associate-/r*86.4%

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv86.4%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval86.4%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr86.4%

    \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Taylor expanded in b around 0 50.7%

    \[\leadsto \frac{\frac{\pi \cdot 0.5}{\color{blue}{a}}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  6. Taylor expanded in a around inf 54.1%

    \[\leadsto \frac{\frac{\pi \cdot 0.5}{a}}{b - a} \cdot \color{blue}{\frac{-1}{b}} \]
  7. Taylor expanded in a around 0 27.6%

    \[\leadsto \color{blue}{\left(0.5 \cdot \frac{\pi}{a \cdot b}\right)} \cdot \frac{-1}{b} \]
  8. Final simplification27.6%

    \[\leadsto \frac{-1}{b} \cdot \left(0.5 \cdot \frac{\pi}{a \cdot b}\right) \]
  9. Add Preprocessing

Reproduce

?
herbie shell --seed 2024163 
(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))))