NMSE Section 6.1 mentioned, B

Percentage Accurate: 77.7% → 99.6%
Time: 4.4s
Alternatives: 7
Speedup: 1.8×

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}

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: 77.7% 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, 1.7× speedup?

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

\\
\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \frac{1}{b \cdot a}
\end{array}
Derivation
  1. Initial program 77.7%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. lift-/.f64N/A

      \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{1}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. lift--.f64N/A

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. lift-*.f64N/A

      \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b} - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. lift-*.f64N/A

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

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

      \[\leadsto \frac{\frac{\pi}{2} \cdot 1}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    8. times-fracN/A

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    9. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    10. lower-/.f64N/A

      \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    11. lower-+.f64N/A

      \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    12. lower-/.f64N/A

      \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    13. lower--.f6487.9

      \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  4. Applied rewrites87.9%

    \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)} \]
    2. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    3. lift-+.f64N/A

      \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. lift-/.f64N/A

      \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. lift-PI.f64N/A

      \[\leadsto \left(\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    6. lift-/.f64N/A

      \[\leadsto \left(\frac{\color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    7. lift--.f64N/A

      \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    8. lift-/.f64N/A

      \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    9. lift--.f64N/A

      \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right)} \]
    10. lift-/.f64N/A

      \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\color{blue}{\frac{1}{a}} - \frac{1}{b}\right) \]
    11. lift-/.f64N/A

      \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \color{blue}{\frac{1}{b}}\right) \]
    12. associate-*l*N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    13. lower-*.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
  6. Applied rewrites99.6%

    \[\leadsto \color{blue}{\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \left({\left(b - a\right)}^{-1} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)} \]
  7. Taylor expanded in a around 0

    \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \color{blue}{\frac{1}{a \cdot b}} \]
  8. Step-by-step derivation
    1. inv-powN/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(a \cdot b\right)}^{\color{blue}{-1}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(a \cdot b\right)}^{\color{blue}{-1}} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(b \cdot a\right)}^{-1} \]
    4. lower-*.f6499.6

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(b \cdot a\right)}^{-1} \]
  9. Applied rewrites99.6%

    \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \color{blue}{{\left(b \cdot a\right)}^{-1}} \]
  10. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(b \cdot a\right)}^{-1} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot {\left(b \cdot a\right)}^{\color{blue}{-1}} \]
    3. unpow-1N/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \frac{1}{\color{blue}{b \cdot a}} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \frac{1}{\color{blue}{b \cdot a}} \]
    5. lift-*.f6499.6

      \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \frac{1}{b \cdot \color{blue}{a}} \]
  11. Applied rewrites99.6%

    \[\leadsto \frac{\pi}{2 \cdot \left(a + b\right)} \cdot \frac{1}{\color{blue}{b \cdot a}} \]
  12. Add Preprocessing

Alternative 2: 86.9% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{\pi}{b} \cdot 0.5}{a}}{a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= b -1.85e+17) (not (<= b 7e-14)))
   (* (/ PI (* b (* b a))) 0.5)
   (/ (/ (* (/ PI b) 0.5) a) a)))
double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (((double) M_PI) / (b * (b * a))) * 0.5;
	} else {
		tmp = (((((double) M_PI) / b) * 0.5) / a) / a;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (Math.PI / (b * (b * a))) * 0.5;
	} else {
		tmp = (((Math.PI / b) * 0.5) / a) / a;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (b <= -1.85e+17) or not (b <= 7e-14):
		tmp = (math.pi / (b * (b * a))) * 0.5
	else:
		tmp = (((math.pi / b) * 0.5) / a) / a
	return tmp
function code(a, b)
	tmp = 0.0
	if ((b <= -1.85e+17) || !(b <= 7e-14))
		tmp = Float64(Float64(pi / Float64(b * Float64(b * a))) * 0.5);
	else
		tmp = Float64(Float64(Float64(Float64(pi / b) * 0.5) / a) / a);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((b <= -1.85e+17) || ~((b <= 7e-14)))
		tmp = (pi / (b * (b * a))) * 0.5;
	else
		tmp = (((pi / b) * 0.5) / a) / a;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[b, -1.85e+17], N[Not[LessEqual[b, 7e-14]], $MachinePrecision]], N[(N[(Pi / N[(b * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(N[(N[(Pi / b), $MachinePrecision] * 0.5), $MachinePrecision] / a), $MachinePrecision] / a), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\
\;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.85e17 or 7.0000000000000005e-14 < b

    1. Initial program 74.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. lift-/.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{1}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift--.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-*.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b} - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-*.f64N/A

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

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

        \[\leadsto \frac{\frac{\pi}{2} \cdot 1}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      10. lower-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      11. lower-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      12. lower-/.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      13. lower--.f6488.4

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied rewrites88.4%

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-PI.f64N/A

        \[\leadsto \left(\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      6. lift-/.f64N/A

        \[\leadsto \left(\frac{\color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      7. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right)} \]
      10. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\color{blue}{\frac{1}{a}} - \frac{1}{b}\right) \]
      11. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \color{blue}{\frac{1}{b}}\right) \]
      12. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      13. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    6. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \left({\left(b - a\right)}^{-1} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)} \]
    7. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}}} \]
    8. Step-by-step derivation
      1. associate-/r*N/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      3. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      4. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      5. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      6. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      7. frac-subN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      8. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      11. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      14. pow2N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      15. lift-*.f6479.1

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5 \]
    9. Applied rewrites79.1%

      \[\leadsto \color{blue}{\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      5. lift-*.f6490.5

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5 \]
    11. Applied rewrites90.5%

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

    if -1.85e17 < b < 7.0000000000000005e-14

    1. Initial program 80.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a} + \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b}}{{a}^{2}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a} + \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b}}{\color{blue}{{a}^{2}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b} + \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}}{{\color{blue}{a}}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}}{{a}^{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\mathsf{PI}\left(\right)}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{\color{blue}{a}}^{2}} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\mathsf{PI}\left(\right)}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{a}^{2}} \]
      6. lift-PI.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{a}^{2}} \]
      7. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      10. lift-PI.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      11. pow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{a \cdot \color{blue}{a}} \]
      12. lift-*.f6462.6

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, 0.5, \frac{\pi}{a} \cdot -0.5\right)}{a \cdot \color{blue}{a}} \]
    5. Applied rewrites62.6%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\frac{\pi}{b}, 0.5, \frac{\pi}{a} \cdot -0.5\right)}{a \cdot a}} \]
    6. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{\color{blue}{a \cdot a}} \]
      2. lift-fma.f64N/A

        \[\leadsto \frac{\frac{\pi}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{\color{blue}{a} \cdot a} \]
      3. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      6. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      8. lift-*.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot \color{blue}{a}} \]
      9. associate-/r*N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a}}{\color{blue}{a}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a}}{\color{blue}{a}} \]
    7. Applied rewrites75.4%

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(\frac{\pi}{a}, -0.5, \frac{\pi}{b} \cdot 0.5\right)}{a}}{a}} \]
    8. Taylor expanded in a around inf

      \[\leadsto \frac{\frac{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b}}{a}}{a} \]
    9. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2}}{a}}{a} \]
      2. lift-/.f64N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2}}{a}}{a} \]
      3. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\frac{\pi}{b} \cdot \frac{1}{2}}{a}}{a} \]
      4. lift-*.f6483.5

        \[\leadsto \frac{\frac{\frac{\pi}{b} \cdot 0.5}{a}}{a} \]
    10. Applied rewrites83.5%

      \[\leadsto \frac{\frac{\frac{\pi}{b} \cdot 0.5}{a}}{a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{\pi}{b} \cdot 0.5}{a}}{a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 87.0% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{\pi}{a}}{b} \cdot 0.5}{a}\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= b -1.85e+17) (not (<= b 7e-14)))
   (* (/ PI (* b (* b a))) 0.5)
   (/ (* (/ (/ PI a) b) 0.5) a)))
double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (((double) M_PI) / (b * (b * a))) * 0.5;
	} else {
		tmp = (((((double) M_PI) / a) / b) * 0.5) / a;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (Math.PI / (b * (b * a))) * 0.5;
	} else {
		tmp = (((Math.PI / a) / b) * 0.5) / a;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (b <= -1.85e+17) or not (b <= 7e-14):
		tmp = (math.pi / (b * (b * a))) * 0.5
	else:
		tmp = (((math.pi / a) / b) * 0.5) / a
	return tmp
function code(a, b)
	tmp = 0.0
	if ((b <= -1.85e+17) || !(b <= 7e-14))
		tmp = Float64(Float64(pi / Float64(b * Float64(b * a))) * 0.5);
	else
		tmp = Float64(Float64(Float64(Float64(pi / a) / b) * 0.5) / a);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((b <= -1.85e+17) || ~((b <= 7e-14)))
		tmp = (pi / (b * (b * a))) * 0.5;
	else
		tmp = (((pi / a) / b) * 0.5) / a;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[b, -1.85e+17], N[Not[LessEqual[b, 7e-14]], $MachinePrecision]], N[(N[(Pi / N[(b * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(N[(N[(Pi / a), $MachinePrecision] / b), $MachinePrecision] * 0.5), $MachinePrecision] / a), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\
\;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.85e17 or 7.0000000000000005e-14 < b

    1. Initial program 74.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. lift-/.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{1}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift--.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-*.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b} - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-*.f64N/A

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

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

        \[\leadsto \frac{\frac{\pi}{2} \cdot 1}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      10. lower-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      11. lower-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      12. lower-/.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      13. lower--.f6488.4

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied rewrites88.4%

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-PI.f64N/A

        \[\leadsto \left(\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      6. lift-/.f64N/A

        \[\leadsto \left(\frac{\color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      7. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right)} \]
      10. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\color{blue}{\frac{1}{a}} - \frac{1}{b}\right) \]
      11. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \color{blue}{\frac{1}{b}}\right) \]
      12. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      13. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    6. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \left({\left(b - a\right)}^{-1} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)} \]
    7. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}}} \]
    8. Step-by-step derivation
      1. associate-/r*N/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      3. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      4. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      5. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      6. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      7. frac-subN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      8. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      11. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      14. pow2N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      15. lift-*.f6479.1

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5 \]
    9. Applied rewrites79.1%

      \[\leadsto \color{blue}{\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      5. lift-*.f6490.5

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5 \]
    11. Applied rewrites90.5%

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

    if -1.85e17 < b < 7.0000000000000005e-14

    1. Initial program 80.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a} + \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b}}{{a}^{2}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a} + \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b}}{\color{blue}{{a}^{2}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{b} + \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}}{{\color{blue}{a}}^{2}} \]
      3. *-commutativeN/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}}{{a}^{2}} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\mathsf{PI}\left(\right)}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{\color{blue}{a}}^{2}} \]
      5. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\mathsf{PI}\left(\right)}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{a}^{2}} \]
      6. lift-PI.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{-1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a}\right)}{{a}^{2}} \]
      7. *-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      10. lift-PI.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{{a}^{2}} \]
      11. pow2N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{a \cdot \color{blue}{a}} \]
      12. lift-*.f6462.6

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, 0.5, \frac{\pi}{a} \cdot -0.5\right)}{a \cdot \color{blue}{a}} \]
    5. Applied rewrites62.6%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\frac{\pi}{b}, 0.5, \frac{\pi}{a} \cdot -0.5\right)}{a \cdot a}} \]
    6. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(\frac{\pi}{b}, \frac{1}{2}, \frac{\pi}{a} \cdot \frac{-1}{2}\right)}{\color{blue}{a \cdot a}} \]
      2. lift-fma.f64N/A

        \[\leadsto \frac{\frac{\pi}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{\color{blue}{a} \cdot a} \]
      3. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\pi}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      6. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot a} \]
      8. lift-*.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a \cdot \color{blue}{a}} \]
      9. associate-/r*N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a}}{\color{blue}{a}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{b} \cdot \frac{1}{2} + \frac{\mathsf{PI}\left(\right)}{a} \cdot \frac{-1}{2}}{a}}{\color{blue}{a}} \]
    7. Applied rewrites75.4%

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(\frac{\pi}{a}, -0.5, \frac{\pi}{b} \cdot 0.5\right)}{a}}{a}} \]
    8. Taylor expanded in a around inf

      \[\leadsto \frac{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot b}}{a} \]
    9. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{a \cdot b} \cdot \frac{1}{2}}{a} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{a \cdot b} \cdot \frac{1}{2}}{a} \]
      3. associate-/r*N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{a}}{b} \cdot \frac{1}{2}}{a} \]
      4. lower-/.f64N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{a}}{b} \cdot \frac{1}{2}}{a} \]
      5. lift-/.f64N/A

        \[\leadsto \frac{\frac{\frac{\mathsf{PI}\left(\right)}{a}}{b} \cdot \frac{1}{2}}{a} \]
      6. lift-PI.f6483.5

        \[\leadsto \frac{\frac{\frac{\pi}{a}}{b} \cdot 0.5}{a} \]
    10. Applied rewrites83.5%

      \[\leadsto \frac{\frac{\frac{\pi}{a}}{b} \cdot 0.5}{a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification87.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{\pi}{a}}{b} \cdot 0.5}{a}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 86.9% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\pi}{a}}{b \cdot a} \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= b -1.85e+17) (not (<= b 7e-14)))
   (* (/ PI (* b (* b a))) 0.5)
   (* (/ (/ PI a) (* b a)) 0.5)))
double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (((double) M_PI) / (b * (b * a))) * 0.5;
	} else {
		tmp = ((((double) M_PI) / a) / (b * a)) * 0.5;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (Math.PI / (b * (b * a))) * 0.5;
	} else {
		tmp = ((Math.PI / a) / (b * a)) * 0.5;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (b <= -1.85e+17) or not (b <= 7e-14):
		tmp = (math.pi / (b * (b * a))) * 0.5
	else:
		tmp = ((math.pi / a) / (b * a)) * 0.5
	return tmp
function code(a, b)
	tmp = 0.0
	if ((b <= -1.85e+17) || !(b <= 7e-14))
		tmp = Float64(Float64(pi / Float64(b * Float64(b * a))) * 0.5);
	else
		tmp = Float64(Float64(Float64(pi / a) / Float64(b * a)) * 0.5);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((b <= -1.85e+17) || ~((b <= 7e-14)))
		tmp = (pi / (b * (b * a))) * 0.5;
	else
		tmp = ((pi / a) / (b * a)) * 0.5;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[b, -1.85e+17], N[Not[LessEqual[b, 7e-14]], $MachinePrecision]], N[(N[(Pi / N[(b * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(N[(Pi / a), $MachinePrecision] / N[(b * a), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\
\;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.85e17 or 7.0000000000000005e-14 < b

    1. Initial program 74.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. lift-/.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{1}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift--.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-*.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b} - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-*.f64N/A

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

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

        \[\leadsto \frac{\frac{\pi}{2} \cdot 1}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      10. lower-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      11. lower-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      12. lower-/.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      13. lower--.f6488.4

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied rewrites88.4%

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-PI.f64N/A

        \[\leadsto \left(\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      6. lift-/.f64N/A

        \[\leadsto \left(\frac{\color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      7. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right)} \]
      10. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\color{blue}{\frac{1}{a}} - \frac{1}{b}\right) \]
      11. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \color{blue}{\frac{1}{b}}\right) \]
      12. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      13. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    6. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \left({\left(b - a\right)}^{-1} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)} \]
    7. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}}} \]
    8. Step-by-step derivation
      1. associate-/r*N/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      3. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      4. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      5. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      6. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      7. frac-subN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      8. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      11. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      14. pow2N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      15. lift-*.f6479.1

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5 \]
    9. Applied rewrites79.1%

      \[\leadsto \color{blue}{\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      5. lift-*.f6490.5

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5 \]
    11. Applied rewrites90.5%

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

    if -1.85e17 < b < 7.0000000000000005e-14

    1. Initial program 80.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      4. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      6. pow2N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      7. lift-*.f6470.7

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5 \]
    5. Applied rewrites70.7%

      \[\leadsto \color{blue}{\frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      5. lower-*.f6483.0

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
    7. Applied rewrites83.0%

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
    8. Step-by-step derivation
      1. lift-PI.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      2. lift-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      5. associate-/r*N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{a}}{a \cdot b} \cdot \frac{1}{2} \]
      6. lower-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{a}}{a \cdot b} \cdot \frac{1}{2} \]
      7. lift-/.f64N/A

        \[\leadsto \frac{\frac{\mathsf{PI}\left(\right)}{a}}{a \cdot b} \cdot \frac{1}{2} \]
      8. lift-PI.f64N/A

        \[\leadsto \frac{\frac{\pi}{a}}{a \cdot b} \cdot \frac{1}{2} \]
      9. *-commutativeN/A

        \[\leadsto \frac{\frac{\pi}{a}}{b \cdot a} \cdot \frac{1}{2} \]
      10. lower-*.f6483.5

        \[\leadsto \frac{\frac{\pi}{a}}{b \cdot a} \cdot 0.5 \]
    9. Applied rewrites83.5%

      \[\leadsto \frac{\frac{\pi}{a}}{b \cdot a} \cdot 0.5 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\pi}{a}}{b \cdot a} \cdot 0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 86.7% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= b -1.85e+17) (not (<= b 7e-14)))
   (* (/ PI (* b (* b a))) 0.5)
   (* (/ PI (* a (* a b))) 0.5)))
double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (((double) M_PI) / (b * (b * a))) * 0.5;
	} else {
		tmp = (((double) M_PI) / (a * (a * b))) * 0.5;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (Math.PI / (b * (b * a))) * 0.5;
	} else {
		tmp = (Math.PI / (a * (a * b))) * 0.5;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (b <= -1.85e+17) or not (b <= 7e-14):
		tmp = (math.pi / (b * (b * a))) * 0.5
	else:
		tmp = (math.pi / (a * (a * b))) * 0.5
	return tmp
function code(a, b)
	tmp = 0.0
	if ((b <= -1.85e+17) || !(b <= 7e-14))
		tmp = Float64(Float64(pi / Float64(b * Float64(b * a))) * 0.5);
	else
		tmp = Float64(Float64(pi / Float64(a * Float64(a * b))) * 0.5);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((b <= -1.85e+17) || ~((b <= 7e-14)))
		tmp = (pi / (b * (b * a))) * 0.5;
	else
		tmp = (pi / (a * (a * b))) * 0.5;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[b, -1.85e+17], N[Not[LessEqual[b, 7e-14]], $MachinePrecision]], N[(N[(Pi / N[(b * N[(b * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(Pi / N[(a * N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\
\;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.85e17 or 7.0000000000000005e-14 < b

    1. Initial program 74.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      2. lift-/.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \color{blue}{\frac{1}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift--.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b - a \cdot a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-*.f64N/A

        \[\leadsto \left(\frac{\pi}{2} \cdot \frac{1}{\color{blue}{b \cdot b} - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-*.f64N/A

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

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

        \[\leadsto \frac{\frac{\pi}{2} \cdot 1}{\color{blue}{\left(b + a\right) \cdot \left(b - a\right)}} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      10. lower-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      11. lower-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      12. lower-/.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      13. lower--.f6488.4

        \[\leadsto \left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    4. Applied rewrites88.4%

      \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    5. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\frac{\frac{\pi}{2}}{b + a} \cdot \frac{1}{b - a}\right)} \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      3. lift-+.f64N/A

        \[\leadsto \left(\frac{\frac{\pi}{2}}{\color{blue}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      4. lift-/.f64N/A

        \[\leadsto \left(\color{blue}{\frac{\frac{\pi}{2}}{b + a}} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      5. lift-PI.f64N/A

        \[\leadsto \left(\frac{\frac{\color{blue}{\mathsf{PI}\left(\right)}}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      6. lift-/.f64N/A

        \[\leadsto \left(\frac{\color{blue}{\frac{\mathsf{PI}\left(\right)}{2}}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      7. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{\color{blue}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      8. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \color{blue}{\frac{1}{b - a}}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
      9. lift--.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \color{blue}{\left(\frac{1}{a} - \frac{1}{b}\right)} \]
      10. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\color{blue}{\frac{1}{a}} - \frac{1}{b}\right) \]
      11. lift-/.f64N/A

        \[\leadsto \left(\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \frac{1}{b - a}\right) \cdot \left(\frac{1}{a} - \color{blue}{\frac{1}{b}}\right) \]
      12. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
      13. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\mathsf{PI}\left(\right)}{2}}{b + a} \cdot \left(\frac{1}{b - a} \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\right)} \]
    6. Applied rewrites99.6%

      \[\leadsto \color{blue}{\frac{\pi}{2 \cdot \left(a + b\right)} \cdot \left({\left(b - a\right)}^{-1} \cdot \left({a}^{-1} - {b}^{-1}\right)\right)} \]
    7. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}}} \]
    8. Step-by-step derivation
      1. associate-/r*N/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      3. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      4. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      5. inv-powN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      6. associate-*l*N/A

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      7. frac-subN/A

        \[\leadsto \frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \]
      8. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      11. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      12. *-commutativeN/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      14. pow2N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      15. lift-*.f6479.1

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5 \]
    9. Applied rewrites79.1%

      \[\leadsto \color{blue}{\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot \frac{1}{2} \]
      5. lift-*.f6490.5

        \[\leadsto \frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5 \]
    11. Applied rewrites90.5%

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

    if -1.85e17 < b < 7.0000000000000005e-14

    1. Initial program 80.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      4. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      6. pow2N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      7. lift-*.f6470.7

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5 \]
    5. Applied rewrites70.7%

      \[\leadsto \color{blue}{\frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      5. lower-*.f6483.0

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
    7. Applied rewrites83.0%

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{b \cdot \left(b \cdot a\right)} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 81.0% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (or (<= b -1.85e+17) (not (<= b 7e-14)))
   (* (/ PI (* (* b b) a)) 0.5)
   (* (/ PI (* a (* a b))) 0.5)))
double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (((double) M_PI) / ((b * b) * a)) * 0.5;
	} else {
		tmp = (((double) M_PI) / (a * (a * b))) * 0.5;
	}
	return tmp;
}
public static double code(double a, double b) {
	double tmp;
	if ((b <= -1.85e+17) || !(b <= 7e-14)) {
		tmp = (Math.PI / ((b * b) * a)) * 0.5;
	} else {
		tmp = (Math.PI / (a * (a * b))) * 0.5;
	}
	return tmp;
}
def code(a, b):
	tmp = 0
	if (b <= -1.85e+17) or not (b <= 7e-14):
		tmp = (math.pi / ((b * b) * a)) * 0.5
	else:
		tmp = (math.pi / (a * (a * b))) * 0.5
	return tmp
function code(a, b)
	tmp = 0.0
	if ((b <= -1.85e+17) || !(b <= 7e-14))
		tmp = Float64(Float64(pi / Float64(Float64(b * b) * a)) * 0.5);
	else
		tmp = Float64(Float64(pi / Float64(a * Float64(a * b))) * 0.5);
	end
	return tmp
end
function tmp_2 = code(a, b)
	tmp = 0.0;
	if ((b <= -1.85e+17) || ~((b <= 7e-14)))
		tmp = (pi / ((b * b) * a)) * 0.5;
	else
		tmp = (pi / (a * (a * b))) * 0.5;
	end
	tmp_2 = tmp;
end
code[a_, b_] := If[Or[LessEqual[b, -1.85e+17], N[Not[LessEqual[b, 7e-14]], $MachinePrecision]], N[(N[(Pi / N[(N[(b * b), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision], N[(N[(Pi / N[(a * N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\
\;\;\;\;\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < -1.85e17 or 7.0000000000000005e-14 < b

    1. Initial program 74.9%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \color{blue}{\frac{1}{2}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      4. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{a \cdot {b}^{2}} \cdot \frac{1}{2} \]
      5. *-commutativeN/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{b}^{2} \cdot a} \cdot \frac{1}{2} \]
      7. pow2N/A

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot \frac{1}{2} \]
      8. lift-*.f6479.1

        \[\leadsto \frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5 \]
    5. Applied rewrites79.1%

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

    if -1.85e17 < b < 7.0000000000000005e-14

    1. Initial program 80.4%

      \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      4. lift-PI.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
      6. pow2N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      7. lift-*.f6470.7

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5 \]
    5. Applied rewrites70.7%

      \[\leadsto \color{blue}{\frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
      2. lift-*.f64N/A

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

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
      5. lower-*.f6483.0

        \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
    7. Applied rewrites83.0%

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -1.85 \cdot 10^{+17} \lor \neg \left(b \leq 7 \cdot 10^{-14}\right):\\ \;\;\;\;\frac{\pi}{\left(b \cdot b\right) \cdot a} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 63.3% accurate, 2.6× speedup?

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

\\
\frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5
\end{array}
Derivation
  1. Initial program 77.7%

    \[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \color{blue}{\frac{1}{2}} \]
    3. lower-/.f64N/A

      \[\leadsto \frac{\mathsf{PI}\left(\right)}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
    4. lift-PI.f64N/A

      \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
    5. lower-*.f64N/A

      \[\leadsto \frac{\pi}{{a}^{2} \cdot b} \cdot \frac{1}{2} \]
    6. pow2N/A

      \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
    7. lift-*.f6457.0

      \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5 \]
  5. Applied rewrites57.0%

    \[\leadsto \color{blue}{\frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot 0.5} \]
  6. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{\pi}{\left(a \cdot a\right) \cdot b} \cdot \frac{1}{2} \]
    2. lift-*.f64N/A

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

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot \frac{1}{2} \]
    5. lower-*.f6463.3

      \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
  7. Applied rewrites63.3%

    \[\leadsto \frac{\pi}{a \cdot \left(a \cdot b\right)} \cdot 0.5 \]
  8. Final simplification63.3%

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

Reproduce

?
herbie shell --seed 2025086 
(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))))