NMSE Section 6.1 mentioned, B

Percentage Accurate: 78.2% → 99.6%
Time: 14.4s
Alternatives: 6
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 6 alternatives:

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

Initial Program: 78.2% accurate, 1.0× speedup?

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

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

Alternative 1: 99.6% accurate, 1.1× speedup?

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

\\
\frac{\frac{\left(\pi \cdot 0.5\right) \cdot \left(\frac{-1}{b} + \frac{1}{a}\right)}{b + a}}{b - a}
\end{array}
Derivation
  1. Initial program 78.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*78.5%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. *-rgt-identity78.5%

      \[\leadsto \frac{\color{blue}{\pi \cdot 1}}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    3. associate-/l*78.5%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    4. metadata-eval78.5%

      \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    5. associate-*l/78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    6. *-lft-identity78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    7. sub-neg78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
    8. distribute-neg-frac78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
    9. metadata-eval78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b \cdot b - a \cdot a} \]
  3. Simplified78.4%

    \[\leadsto \color{blue}{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. metadata-eval78.4%

      \[\leadsto \left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
    2. div-inv78.4%

      \[\leadsto \color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
    3. associate-*r/78.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)}{b \cdot b - a \cdot a}} \]
    4. *-commutative78.5%

      \[\leadsto \frac{\color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}}{b \cdot b - a \cdot a} \]
    5. difference-of-squares84.7%

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

      \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}{b + a}}{b - a}} \]
  6. Applied egg-rr65.2%

    \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{1}{b}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a}} \]
  7. Step-by-step derivation
    1. +-commutative65.2%

      \[\leadsto \frac{\frac{\color{blue}{\left(\frac{1}{b} + \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    2. add-sqr-sqrt29.5%

      \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    3. sqrt-unprod76.1%

      \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b} \cdot \frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    4. frac-times76.1%

      \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{1 \cdot 1}{b \cdot b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    5. metadata-eval76.1%

      \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    6. metadata-eval76.1%

      \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{-1 \cdot -1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    7. frac-times76.1%

      \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{-1}{b} \cdot \frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    8. sqrt-unprod53.7%

      \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    9. add-sqr-sqrt99.6%

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

      \[\leadsto \frac{\frac{\left(\color{blue}{-1 \cdot \frac{1}{b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    11. fma-define99.6%

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

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-1, \frac{1}{b}, \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
  9. Step-by-step derivation
    1. fma-undefine99.6%

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

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

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

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

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

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

Alternative 2: 99.6% accurate, 1.1× speedup?

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

\\
\frac{\pi \cdot 0.5}{b + a} \cdot \frac{\frac{-1}{b} + \frac{1}{a}}{b - a}
\end{array}
Derivation
  1. Initial program 78.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv78.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares84.7%

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

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv87.2%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval87.2%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr87.2%

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

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

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

      \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{a + b}} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
    5. sub-neg99.6%

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

      \[\leadsto \frac{0.5 \cdot \pi}{a + b} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
    7. metadata-eval99.6%

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

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

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

Alternative 3: 75.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{-170}:\\ \;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a - b} \cdot \frac{\frac{-0.5}{a}}{b + a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1.15e-170)
   (/ (/ (* PI -0.5) (* b a)) (- b a))
   (* (/ PI (- a b)) (/ (/ -0.5 a) (+ b a)))))
double code(double a, double b) {
	double tmp;
	if (b <= 1.15e-170) {
		tmp = ((((double) M_PI) * -0.5) / (b * a)) / (b - a);
	} else {
		tmp = (((double) M_PI) / (a - b)) * ((-0.5 / a) / (b + a));
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 1.15e-170) {
		tmp = ((Math.PI * -0.5) / (b * a)) / (b - a);
	} else {
		tmp = (Math.PI / (a - b)) * ((-0.5 / a) / (b + a));
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 1.15e-170:
		tmp = ((math.pi * -0.5) / (b * a)) / (b - a)
	else:
		tmp = (math.pi / (a - b)) * ((-0.5 / a) / (b + a))
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 1.15e-170)
		tmp = Float64(Float64(Float64(pi * -0.5) / Float64(b * a)) / Float64(b - a));
	else
		tmp = Float64(Float64(pi / Float64(a - b)) * Float64(Float64(-0.5 / a) / Float64(b + a)));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 1.15e-170)
		tmp = ((pi * -0.5) / (b * a)) / (b - a);
	else
		tmp = (pi / (a - b)) * ((-0.5 / a) / (b + a));
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 1.15e-170], N[(N[(N[(Pi * -0.5), $MachinePrecision] / N[(b * a), $MachinePrecision]), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision], N[(N[(Pi / N[(a - b), $MachinePrecision]), $MachinePrecision] * N[(N[(-0.5 / a), $MachinePrecision] / N[(b + a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.15 \cdot 10^{-170}:\\
\;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.14999999999999993e-170

    1. Initial program 74.6%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. associate-*l*74.7%

        \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      2. *-rgt-identity74.7%

        \[\leadsto \frac{\color{blue}{\pi \cdot 1}}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      3. associate-/l*74.7%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      4. metadata-eval74.7%

        \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      5. associate-*l/74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
      6. *-lft-identity74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
      7. sub-neg74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
      8. distribute-neg-frac74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
      9. metadata-eval74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b \cdot b - a \cdot a} \]
    3. Simplified74.6%

      \[\leadsto \color{blue}{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. metadata-eval74.6%

        \[\leadsto \left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
      2. div-inv74.6%

        \[\leadsto \color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
      3. associate-*r/74.6%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)}{b \cdot b - a \cdot a}} \]
      4. *-commutative74.6%

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

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

        \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}{b + a}}{b - a}} \]
    6. Applied egg-rr58.4%

      \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{1}{b}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a}} \]
    7. Step-by-step derivation
      1. +-commutative58.4%

        \[\leadsto \frac{\frac{\color{blue}{\left(\frac{1}{b} + \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      2. add-sqr-sqrt1.4%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      3. sqrt-unprod75.9%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b} \cdot \frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      4. frac-times75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{1 \cdot 1}{b \cdot b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      5. metadata-eval75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      6. metadata-eval75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{-1 \cdot -1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      7. frac-times75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{-1}{b} \cdot \frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      8. sqrt-unprod85.9%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      9. add-sqr-sqrt99.7%

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

        \[\leadsto \frac{\frac{\left(\color{blue}{-1 \cdot \frac{1}{b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      11. fma-define99.7%

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-1, \frac{1}{b}, \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    9. Step-by-step derivation
      1. fma-undefine99.7%

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

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

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

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\frac{-1}{b} + \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    11. Taylor expanded in b around 0 68.6%

      \[\leadsto \frac{\color{blue}{-0.5 \cdot \frac{\pi}{a \cdot b}}}{b - a} \]
    12. Step-by-step derivation
      1. associate-*r/68.6%

        \[\leadsto \frac{\color{blue}{\frac{-0.5 \cdot \pi}{a \cdot b}}}{b - a} \]
      2. *-commutative68.6%

        \[\leadsto \frac{\frac{-0.5 \cdot \pi}{\color{blue}{b \cdot a}}}{b - a} \]
    13. Simplified68.6%

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

    if 1.14999999999999993e-170 < b

    1. Initial program 84.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. un-div-inv84.9%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. difference-of-squares85.9%

        \[\leadsto \frac{\frac{\pi}{2}}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. associate-/r*88.0%

        \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. div-inv88.0%

        \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. metadata-eval88.0%

        \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied egg-rr88.0%

      \[\leadsto \color{blue}{\frac{\frac{\pi \cdot 0.5}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Taylor expanded in a around 0 66.5%

      \[\leadsto \frac{\frac{\pi \cdot 0.5}{b + a}}{b - a} \cdot \color{blue}{\frac{1}{a}} \]
    6. Step-by-step derivation
      1. associate-/l/65.1%

        \[\leadsto \color{blue}{\frac{\pi \cdot 0.5}{\left(b - a\right) \cdot \left(b + a\right)}} \cdot \frac{1}{a} \]
      2. *-commutative65.1%

        \[\leadsto \frac{\color{blue}{0.5 \cdot \pi}}{\left(b - a\right) \cdot \left(b + a\right)} \cdot \frac{1}{a} \]
      3. *-commutative65.1%

        \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \frac{1}{a} \]
      4. frac-2neg65.1%

        \[\leadsto \frac{0.5 \cdot \pi}{\left(b + a\right) \cdot \left(b - a\right)} \cdot \color{blue}{\frac{-1}{-a}} \]
      5. metadata-eval65.1%

        \[\leadsto \frac{0.5 \cdot \pi}{\left(b + a\right) \cdot \left(b - a\right)} \cdot \frac{\color{blue}{-1}}{-a} \]
      6. frac-times65.1%

        \[\leadsto \color{blue}{\frac{\left(0.5 \cdot \pi\right) \cdot -1}{\left(\left(b + a\right) \cdot \left(b - a\right)\right) \cdot \left(-a\right)}} \]
      7. *-commutative65.1%

        \[\leadsto \frac{\left(0.5 \cdot \pi\right) \cdot -1}{\color{blue}{\left(\left(b - a\right) \cdot \left(b + a\right)\right)} \cdot \left(-a\right)} \]
      8. +-commutative65.1%

        \[\leadsto \frac{\left(0.5 \cdot \pi\right) \cdot -1}{\left(\left(b - a\right) \cdot \color{blue}{\left(a + b\right)}\right) \cdot \left(-a\right)} \]
    7. Applied egg-rr65.1%

      \[\leadsto \color{blue}{\frac{\left(0.5 \cdot \pi\right) \cdot -1}{\left(\left(b - a\right) \cdot \left(a + b\right)\right) \cdot \left(-a\right)}} \]
    8. Step-by-step derivation
      1. *-commutative65.1%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(0.5 \cdot \pi\right)}}{\left(\left(b - a\right) \cdot \left(a + b\right)\right) \cdot \left(-a\right)} \]
      2. *-commutative65.1%

        \[\leadsto \frac{-1 \cdot \left(0.5 \cdot \pi\right)}{\color{blue}{\left(-a\right) \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)}} \]
      3. neg-mul-165.1%

        \[\leadsto \frac{\color{blue}{-0.5 \cdot \pi}}{\left(-a\right) \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)} \]
      4. *-commutative65.1%

        \[\leadsto \frac{-\color{blue}{\pi \cdot 0.5}}{\left(-a\right) \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)} \]
      5. distribute-rgt-neg-in65.1%

        \[\leadsto \frac{\color{blue}{\pi \cdot \left(-0.5\right)}}{\left(-a\right) \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)} \]
      6. metadata-eval65.1%

        \[\leadsto \frac{\pi \cdot \color{blue}{-0.5}}{\left(-a\right) \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)} \]
      7. distribute-lft-neg-out65.1%

        \[\leadsto \frac{\pi \cdot -0.5}{\color{blue}{-a \cdot \left(\left(b - a\right) \cdot \left(a + b\right)\right)}} \]
      8. *-commutative65.1%

        \[\leadsto \frac{\pi \cdot -0.5}{-\color{blue}{\left(\left(b - a\right) \cdot \left(a + b\right)\right) \cdot a}} \]
      9. associate-*l*76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{-\color{blue}{\left(b - a\right) \cdot \left(\left(a + b\right) \cdot a\right)}} \]
      10. distribute-lft-neg-in76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\color{blue}{\left(-\left(b - a\right)\right) \cdot \left(\left(a + b\right) \cdot a\right)}} \]
      11. sub-neg76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\left(-\color{blue}{\left(b + \left(-a\right)\right)}\right) \cdot \left(\left(a + b\right) \cdot a\right)} \]
      12. distribute-neg-in76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\color{blue}{\left(\left(-b\right) + \left(-\left(-a\right)\right)\right)} \cdot \left(\left(a + b\right) \cdot a\right)} \]
      13. remove-double-neg76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\left(\left(-b\right) + \color{blue}{a}\right) \cdot \left(\left(a + b\right) \cdot a\right)} \]
      14. +-commutative76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\color{blue}{\left(a + \left(-b\right)\right)} \cdot \left(\left(a + b\right) \cdot a\right)} \]
      15. unsub-neg76.8%

        \[\leadsto \frac{\pi \cdot -0.5}{\color{blue}{\left(a - b\right)} \cdot \left(\left(a + b\right) \cdot a\right)} \]
    9. Simplified76.8%

      \[\leadsto \color{blue}{\frac{\pi \cdot -0.5}{\left(a - b\right) \cdot \left(\left(a + b\right) \cdot a\right)}} \]
    10. Step-by-step derivation
      1. times-frac76.8%

        \[\leadsto \color{blue}{\frac{\pi}{a - b} \cdot \frac{-0.5}{\left(a + b\right) \cdot a}} \]
      2. +-commutative76.8%

        \[\leadsto \frac{\pi}{a - b} \cdot \frac{-0.5}{\color{blue}{\left(b + a\right)} \cdot a} \]
      3. *-commutative76.8%

        \[\leadsto \frac{\pi}{a - b} \cdot \frac{-0.5}{\color{blue}{a \cdot \left(b + a\right)}} \]
    11. Applied egg-rr76.8%

      \[\leadsto \color{blue}{\frac{\pi}{a - b} \cdot \frac{-0.5}{a \cdot \left(b + a\right)}} \]
    12. Step-by-step derivation
      1. associate-/r*76.7%

        \[\leadsto \frac{\pi}{a - b} \cdot \color{blue}{\frac{\frac{-0.5}{a}}{b + a}} \]
    13. Simplified76.7%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.15 \cdot 10^{-170}:\\ \;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a - b} \cdot \frac{\frac{-0.5}{a}}{b + a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 74.7% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.65 \cdot 10^{-170}:\\ \;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 \cdot \frac{\pi}{b \cdot a}}{b - a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= b 1.65e-170)
   (/ (/ (* PI -0.5) (* b a)) (- b a))
   (/ (* 0.5 (/ PI (* b a))) (- b a))))
double code(double a, double b) {
	double tmp;
	if (b <= 1.65e-170) {
		tmp = ((((double) M_PI) * -0.5) / (b * a)) / (b - a);
	} else {
		tmp = (0.5 * (((double) M_PI) / (b * a))) / (b - a);
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if (b <= 1.65e-170) {
		tmp = ((Math.PI * -0.5) / (b * a)) / (b - a);
	} else {
		tmp = (0.5 * (Math.PI / (b * a))) / (b - a);
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if b <= 1.65e-170:
		tmp = ((math.pi * -0.5) / (b * a)) / (b - a)
	else:
		tmp = (0.5 * (math.pi / (b * a))) / (b - a)
	return tmp
function code(a, b)
	tmp = 0.0
	if (b <= 1.65e-170)
		tmp = Float64(Float64(Float64(pi * -0.5) / Float64(b * a)) / Float64(b - a));
	else
		tmp = Float64(Float64(0.5 * Float64(pi / Float64(b * a))) / Float64(b - a));
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if (b <= 1.65e-170)
		tmp = ((pi * -0.5) / (b * a)) / (b - a);
	else
		tmp = (0.5 * (pi / (b * a))) / (b - a);
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[LessEqual[b, 1.65e-170], N[(N[(N[(Pi * -0.5), $MachinePrecision] / N[(b * a), $MachinePrecision]), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[(Pi / N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b - a), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 1.65 \cdot 10^{-170}:\\
\;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 1.65000000000000002e-170

    1. Initial program 74.6%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. associate-*l*74.7%

        \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      2. *-rgt-identity74.7%

        \[\leadsto \frac{\color{blue}{\pi \cdot 1}}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      3. associate-/l*74.7%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      4. metadata-eval74.7%

        \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      5. associate-*l/74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
      6. *-lft-identity74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
      7. sub-neg74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
      8. distribute-neg-frac74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
      9. metadata-eval74.6%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b \cdot b - a \cdot a} \]
    3. Simplified74.6%

      \[\leadsto \color{blue}{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. metadata-eval74.6%

        \[\leadsto \left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
      2. div-inv74.6%

        \[\leadsto \color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
      3. associate-*r/74.6%

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)}{b \cdot b - a \cdot a}} \]
      4. *-commutative74.6%

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

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

        \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}{b + a}}{b - a}} \]
    6. Applied egg-rr58.4%

      \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{1}{b}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a}} \]
    7. Step-by-step derivation
      1. +-commutative58.4%

        \[\leadsto \frac{\frac{\color{blue}{\left(\frac{1}{b} + \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      2. add-sqr-sqrt1.4%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b}} \cdot \sqrt{\frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      3. sqrt-unprod75.9%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{1}{b} \cdot \frac{1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      4. frac-times75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{1 \cdot 1}{b \cdot b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      5. metadata-eval75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      6. metadata-eval75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\frac{\color{blue}{-1 \cdot -1}}{b \cdot b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      7. frac-times75.9%

        \[\leadsto \frac{\frac{\left(\sqrt{\color{blue}{\frac{-1}{b} \cdot \frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      8. sqrt-unprod85.9%

        \[\leadsto \frac{\frac{\left(\color{blue}{\sqrt{\frac{-1}{b}} \cdot \sqrt{\frac{-1}{b}}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      9. add-sqr-sqrt99.7%

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

        \[\leadsto \frac{\frac{\left(\color{blue}{-1 \cdot \frac{1}{b}} + \frac{1}{a}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
      11. fma-define99.7%

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

      \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(-1, \frac{1}{b}, \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    9. Step-by-step derivation
      1. fma-undefine99.7%

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

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

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

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

      \[\leadsto \frac{\frac{\color{blue}{\left(\frac{-1}{b} + \frac{1}{a}\right)} \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a} \]
    11. Taylor expanded in b around 0 68.6%

      \[\leadsto \frac{\color{blue}{-0.5 \cdot \frac{\pi}{a \cdot b}}}{b - a} \]
    12. Step-by-step derivation
      1. associate-*r/68.6%

        \[\leadsto \frac{\color{blue}{\frac{-0.5 \cdot \pi}{a \cdot b}}}{b - a} \]
      2. *-commutative68.6%

        \[\leadsto \frac{\frac{-0.5 \cdot \pi}{\color{blue}{b \cdot a}}}{b - a} \]
    13. Simplified68.6%

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

    if 1.65000000000000002e-170 < b

    1. Initial program 84.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Step-by-step derivation
      1. associate-*l*85.0%

        \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      2. *-rgt-identity85.0%

        \[\leadsto \frac{\color{blue}{\pi \cdot 1}}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      3. associate-/l*85.0%

        \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      4. metadata-eval85.0%

        \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
      5. associate-*l/84.8%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
      6. *-lft-identity84.8%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
      7. sub-neg84.8%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
      8. distribute-neg-frac84.8%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
      9. metadata-eval84.8%

        \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b \cdot b - a \cdot a} \]
    3. Simplified84.8%

      \[\leadsto \color{blue}{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. metadata-eval84.8%

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

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

        \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)}{b \cdot b - a \cdot a}} \]
      4. *-commutative84.8%

        \[\leadsto \frac{\color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}}{b \cdot b - a \cdot a} \]
      5. difference-of-squares85.9%

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

        \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}{b + a}}{b - a}} \]
    6. Applied egg-rr76.4%

      \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{1}{b}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a}} \]
    7. Taylor expanded in a around 0 76.4%

      \[\leadsto \frac{\color{blue}{0.5 \cdot \frac{\pi}{a \cdot b}}}{b - a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.65 \cdot 10^{-170}:\\ \;\;\;\;\frac{\frac{\pi \cdot -0.5}{b \cdot a}}{b - a}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5 \cdot \frac{\pi}{b \cdot a}}{b - a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.6% accurate, 1.6× speedup?

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

\\
\frac{\pi \cdot 0.5}{b + a} \cdot \frac{1}{b \cdot a}
\end{array}
Derivation
  1. Initial program 78.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. un-div-inv78.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2}}{b \cdot b - a \cdot a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. difference-of-squares84.7%

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

      \[\leadsto \color{blue}{\frac{\frac{\frac{\pi}{2}}{b + a}}{b - a}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. div-inv87.2%

      \[\leadsto \frac{\frac{\color{blue}{\pi \cdot \frac{1}{2}}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. metadata-eval87.2%

      \[\leadsto \frac{\frac{\pi \cdot \color{blue}{0.5}}{b + a}}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied egg-rr87.2%

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

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

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

      \[\leadsto \frac{0.5 \cdot \pi}{\color{blue}{a + b}} \cdot \frac{\frac{1}{a} - \frac{1}{b}}{b - a} \]
    5. sub-neg99.6%

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

      \[\leadsto \frac{0.5 \cdot \pi}{a + b} \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b - a} \]
    7. metadata-eval99.6%

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

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

    \[\leadsto \frac{0.5 \cdot \pi}{a + b} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  10. Final simplification99.6%

    \[\leadsto \frac{\pi \cdot 0.5}{b + a} \cdot \frac{1}{b \cdot a} \]
  11. Add Preprocessing

Alternative 6: 66.7% accurate, 1.9× speedup?

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

\\
\frac{0.5 \cdot \frac{\pi}{b \cdot a}}{b - a}
\end{array}
Derivation
  1. Initial program 78.5%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Step-by-step derivation
    1. associate-*l*78.5%

      \[\leadsto \color{blue}{\frac{\pi}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    2. *-rgt-identity78.5%

      \[\leadsto \frac{\color{blue}{\pi \cdot 1}}{2} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    3. associate-/l*78.5%

      \[\leadsto \color{blue}{\left(\pi \cdot \frac{1}{2}\right)} \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    4. metadata-eval78.5%

      \[\leadsto \left(\pi \cdot \color{blue}{0.5}\right) \cdot \left(\frac{1}{b \cdot b - a \cdot a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right) \]
    5. associate-*l/78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \color{blue}{\frac{1 \cdot \left(\frac{1}{a} - \frac{1}{b}\right)}{b \cdot b - a \cdot a}} \]
    6. *-lft-identity78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} - \frac{1}{b}}}{b \cdot b - a \cdot a} \]
    7. sub-neg78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\color{blue}{\frac{1}{a} + \left(-\frac{1}{b}\right)}}{b \cdot b - a \cdot a} \]
    8. distribute-neg-frac78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \color{blue}{\frac{-1}{b}}}{b \cdot b - a \cdot a} \]
    9. metadata-eval78.4%

      \[\leadsto \left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{\color{blue}{-1}}{b}}{b \cdot b - a \cdot a} \]
  3. Simplified78.4%

    \[\leadsto \color{blue}{\left(\pi \cdot 0.5\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. metadata-eval78.4%

      \[\leadsto \left(\pi \cdot \color{blue}{\frac{1}{2}}\right) \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
    2. div-inv78.4%

      \[\leadsto \color{blue}{\frac{\pi}{2}} \cdot \frac{\frac{1}{a} + \frac{-1}{b}}{b \cdot b - a \cdot a} \]
    3. associate-*r/78.5%

      \[\leadsto \color{blue}{\frac{\frac{\pi}{2} \cdot \left(\frac{1}{a} + \frac{-1}{b}\right)}{b \cdot b - a \cdot a}} \]
    4. *-commutative78.5%

      \[\leadsto \frac{\color{blue}{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}}{b \cdot b - a \cdot a} \]
    5. difference-of-squares84.7%

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

      \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{-1}{b}\right) \cdot \frac{\pi}{2}}{b + a}}{b - a}} \]
  6. Applied egg-rr65.2%

    \[\leadsto \color{blue}{\frac{\frac{\left(\frac{1}{a} + \frac{1}{b}\right) \cdot \left(\pi \cdot 0.5\right)}{b + a}}{b - a}} \]
  7. Taylor expanded in a around 0 65.2%

    \[\leadsto \frac{\color{blue}{0.5 \cdot \frac{\pi}{a \cdot b}}}{b - a} \]
  8. Final simplification65.2%

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

Reproduce

?
herbie shell --seed 2024044 
(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))))