Migdal et al, Equation (51)

Percentage Accurate: 99.4% → 99.5%
Time: 7.0s
Alternatives: 8
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \end{array} \]
(FPCore (k n)
 :precision binary64
 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
	return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
	return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n):
	return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n)
	return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0)))
end
function tmp = code(k, n)
	tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0));
end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\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 8 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: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \end{array} \]
(FPCore (k n)
 :precision binary64
 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
	return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
	return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n):
	return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n)
	return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0)))
end
function tmp = code(k, n)
	tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0));
end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
\end{array}

Alternative 1: 99.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{{\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}} \end{array} \]
(FPCore (k n)
 :precision binary64
 (/ (pow (* (+ PI PI) n) (fma -0.5 k 0.5)) (sqrt k)))
double code(double k, double n) {
	return pow(((((double) M_PI) + ((double) M_PI)) * n), fma(-0.5, k, 0.5)) / sqrt(k);
}
function code(k, n)
	return Float64((Float64(Float64(pi + pi) * n) ^ fma(-0.5, k, 0.5)) / sqrt(k))
end
code[k_, n_] := N[(N[Power[N[(N[(Pi + Pi), $MachinePrecision] * n), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{{\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}} \]
    2. lift-/.f64N/A

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

      \[\leadsto \frac{1}{\color{blue}{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    4. lift-pow.f64N/A

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\color{blue}{\left(\left(2 \cdot \pi\right) \cdot n\right)}}^{\left(\frac{1 - k}{2}\right)} \]
    6. lift-PI.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\color{blue}{\left(2 \cdot \mathsf{PI}\left(\right)\right)} \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    8. lift--.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{\color{blue}{1 - k}}{2}\right)} \]
    9. lift-/.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\color{blue}{\left(\frac{1 - k}{2}\right)}} \]
    10. *-commutativeN/A

      \[\leadsto \color{blue}{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \frac{1}{\sqrt{k}}} \]
    11. mult-flip-revN/A

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
    12. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
  3. Applied rewrites99.5%

    \[\leadsto \color{blue}{\frac{{\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}} \]
  4. Add Preprocessing

Alternative 2: 99.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(1 - k\right)}}{\sqrt{k}} \end{array} \]
(FPCore (k n)
 :precision binary64
 (/ (pow (sqrt (* n (+ PI PI))) (- 1.0 k)) (sqrt k)))
double code(double k, double n) {
	return pow(sqrt((n * (((double) M_PI) + ((double) M_PI)))), (1.0 - k)) / sqrt(k);
}
public static double code(double k, double n) {
	return Math.pow(Math.sqrt((n * (Math.PI + Math.PI))), (1.0 - k)) / Math.sqrt(k);
}
def code(k, n):
	return math.pow(math.sqrt((n * (math.pi + math.pi))), (1.0 - k)) / math.sqrt(k)
function code(k, n)
	return Float64((sqrt(Float64(n * Float64(pi + pi))) ^ Float64(1.0 - k)) / sqrt(k))
end
function tmp = code(k, n)
	tmp = (sqrt((n * (pi + pi))) ^ (1.0 - k)) / sqrt(k);
end
code[k_, n_] := N[(N[Power[N[Sqrt[N[(n * N[(Pi + Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[(1.0 - k), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(1 - k\right)}}{\sqrt{k}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around inf

    \[\leadsto \color{blue}{\frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \sqrt{\frac{1}{k}}}} \]
  3. Step-by-step derivation
    1. sqrt-divN/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \frac{\sqrt{1}}{\color{blue}{\sqrt{k}}}} \]
    2. metadata-evalN/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \frac{1}{\sqrt{\color{blue}{k}}}} \]
    3. associate-/r*N/A

      \[\leadsto \frac{\frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k}}{\color{blue}{\frac{1}{\sqrt{k}}}} \]
    4. mult-flipN/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \color{blue}{\frac{1}{\frac{1}{\sqrt{k}}}} \]
    5. div-flipN/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \frac{\sqrt{k}}{\color{blue}{1}} \]
    6. /-rgt-identityN/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \sqrt{k} \]
    7. lower-*.f64N/A

      \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \color{blue}{\sqrt{k}} \]
  4. Applied rewrites90.9%

    \[\leadsto \color{blue}{\frac{e^{\log \left(\sqrt{\left(\pi + \pi\right) \cdot n}\right) \cdot \left(1 - k\right)}}{k} \cdot \sqrt{k}} \]
  5. Applied rewrites99.4%

    \[\leadsto \color{blue}{\frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(1 - k\right)}}{\sqrt{k}}} \]
  6. Add Preprocessing

Alternative 3: 98.2% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;k \leq 1:\\ \;\;\;\;\frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(-k\right)}}{\sqrt{k}}\\ \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= k 1.0)
   (/ (sqrt (* (+ PI PI) n)) (sqrt k))
   (/ (pow (sqrt (* n (+ PI PI))) (- k)) (sqrt k))))
double code(double k, double n) {
	double tmp;
	if (k <= 1.0) {
		tmp = sqrt(((((double) M_PI) + ((double) M_PI)) * n)) / sqrt(k);
	} else {
		tmp = pow(sqrt((n * (((double) M_PI) + ((double) M_PI)))), -k) / sqrt(k);
	}
	return tmp;
}
public static double code(double k, double n) {
	double tmp;
	if (k <= 1.0) {
		tmp = Math.sqrt(((Math.PI + Math.PI) * n)) / Math.sqrt(k);
	} else {
		tmp = Math.pow(Math.sqrt((n * (Math.PI + Math.PI))), -k) / Math.sqrt(k);
	}
	return tmp;
}
def code(k, n):
	tmp = 0
	if k <= 1.0:
		tmp = math.sqrt(((math.pi + math.pi) * n)) / math.sqrt(k)
	else:
		tmp = math.pow(math.sqrt((n * (math.pi + math.pi))), -k) / math.sqrt(k)
	return tmp
function code(k, n)
	tmp = 0.0
	if (k <= 1.0)
		tmp = Float64(sqrt(Float64(Float64(pi + pi) * n)) / sqrt(k));
	else
		tmp = Float64((sqrt(Float64(n * Float64(pi + pi))) ^ Float64(-k)) / sqrt(k));
	end
	return tmp
end
function tmp_2 = code(k, n)
	tmp = 0.0;
	if (k <= 1.0)
		tmp = sqrt(((pi + pi) * n)) / sqrt(k);
	else
		tmp = (sqrt((n * (pi + pi))) ^ -k) / sqrt(k);
	end
	tmp_2 = tmp;
end
code[k_, n_] := If[LessEqual[k, 1.0], N[(N[Sqrt[N[(N[(Pi + Pi), $MachinePrecision] * n), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision], N[(N[Power[N[Sqrt[N[(n * N[(Pi + Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], (-k)], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;k \leq 1:\\
\;\;\;\;\frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}}\\

\mathbf{else}:\\
\;\;\;\;\frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(-k\right)}}{\sqrt{k}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if k < 1

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}} \]
      2. lift-/.f64N/A

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

        \[\leadsto \frac{1}{\color{blue}{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      4. lift-pow.f64N/A

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

        \[\leadsto \frac{1}{\sqrt{k}} \cdot {\color{blue}{\left(\left(2 \cdot \pi\right) \cdot n\right)}}^{\left(\frac{1 - k}{2}\right)} \]
      6. lift-PI.f64N/A

        \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\color{blue}{\left(2 \cdot \mathsf{PI}\left(\right)\right)} \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      8. lift--.f64N/A

        \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{\color{blue}{1 - k}}{2}\right)} \]
      9. lift-/.f64N/A

        \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\color{blue}{\left(\frac{1 - k}{2}\right)}} \]
      10. *-commutativeN/A

        \[\leadsto \color{blue}{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \frac{1}{\sqrt{k}}} \]
      11. mult-flip-revN/A

        \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
      12. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
    3. Applied rewrites99.5%

      \[\leadsto \color{blue}{\frac{{\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}} \]
    4. Taylor expanded in k around 0

      \[\leadsto \frac{\color{blue}{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}}{\sqrt{k}} \]
    5. Step-by-step derivation
      1. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{k}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
      3. associate-*l*N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      5. count-2-revN/A

        \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      6. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      7. lift-PI.f64N/A

        \[\leadsto \frac{\sqrt{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      8. lift-PI.f64N/A

        \[\leadsto \frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}} \]
      9. lower-sqrt.f6449.9

        \[\leadsto \frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}} \]
    6. Applied rewrites49.9%

      \[\leadsto \frac{\color{blue}{\sqrt{\left(\pi + \pi\right) \cdot n}}}{\sqrt{k}} \]

    if 1 < k

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around inf

      \[\leadsto \color{blue}{\frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \sqrt{\frac{1}{k}}}} \]
    3. Step-by-step derivation
      1. sqrt-divN/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \frac{\sqrt{1}}{\color{blue}{\sqrt{k}}}} \]
      2. metadata-evalN/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k \cdot \frac{1}{\sqrt{\color{blue}{k}}}} \]
      3. associate-/r*N/A

        \[\leadsto \frac{\frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k}}{\color{blue}{\frac{1}{\sqrt{k}}}} \]
      4. mult-flipN/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \color{blue}{\frac{1}{\frac{1}{\sqrt{k}}}} \]
      5. div-flipN/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \frac{\sqrt{k}}{\color{blue}{1}} \]
      6. /-rgt-identityN/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \sqrt{k} \]
      7. lower-*.f64N/A

        \[\leadsto \frac{e^{\frac{1}{2} \cdot \left(\log \left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(1 - k\right)\right)}}{k} \cdot \color{blue}{\sqrt{k}} \]
    4. Applied rewrites90.9%

      \[\leadsto \color{blue}{\frac{e^{\log \left(\sqrt{\left(\pi + \pi\right) \cdot n}\right) \cdot \left(1 - k\right)}}{k} \cdot \sqrt{k}} \]
    5. Applied rewrites99.4%

      \[\leadsto \color{blue}{\frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(1 - k\right)}}{\sqrt{k}}} \]
    6. Taylor expanded in k around inf

      \[\leadsto \frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(-1 \cdot k\right)}}{\sqrt{k}} \]
    7. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(\mathsf{neg}\left(k\right)\right)}}{\sqrt{k}} \]
      2. lower-neg.f6453.0

        \[\leadsto \frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(-k\right)}}{\sqrt{k}} \]
    8. Applied rewrites53.0%

      \[\leadsto \frac{{\left(\sqrt{n \cdot \left(\pi + \pi\right)}\right)}^{\left(-k\right)}}{\sqrt{k}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 74.3% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq 8 \cdot 10^{-43}:\\ \;\;\;\;\frac{\sqrt{\frac{\pi \cdot k}{n} \cdot 2} \cdot n}{k}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n\\ \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= n 8e-43)
   (/ (* (sqrt (* (/ (* PI k) n) 2.0)) n) k)
   (* (sqrt (/ (+ PI PI) (* k n))) n)))
double code(double k, double n) {
	double tmp;
	if (n <= 8e-43) {
		tmp = (sqrt((((((double) M_PI) * k) / n) * 2.0)) * n) / k;
	} else {
		tmp = sqrt(((((double) M_PI) + ((double) M_PI)) / (k * n))) * n;
	}
	return tmp;
}
public static double code(double k, double n) {
	double tmp;
	if (n <= 8e-43) {
		tmp = (Math.sqrt((((Math.PI * k) / n) * 2.0)) * n) / k;
	} else {
		tmp = Math.sqrt(((Math.PI + Math.PI) / (k * n))) * n;
	}
	return tmp;
}
def code(k, n):
	tmp = 0
	if n <= 8e-43:
		tmp = (math.sqrt((((math.pi * k) / n) * 2.0)) * n) / k
	else:
		tmp = math.sqrt(((math.pi + math.pi) / (k * n))) * n
	return tmp
function code(k, n)
	tmp = 0.0
	if (n <= 8e-43)
		tmp = Float64(Float64(sqrt(Float64(Float64(Float64(pi * k) / n) * 2.0)) * n) / k);
	else
		tmp = Float64(sqrt(Float64(Float64(pi + pi) / Float64(k * n))) * n);
	end
	return tmp
end
function tmp_2 = code(k, n)
	tmp = 0.0;
	if (n <= 8e-43)
		tmp = (sqrt((((pi * k) / n) * 2.0)) * n) / k;
	else
		tmp = sqrt(((pi + pi) / (k * n))) * n;
	end
	tmp_2 = tmp;
end
code[k_, n_] := If[LessEqual[n, 8e-43], N[(N[(N[Sqrt[N[(N[(N[(Pi * k), $MachinePrecision] / n), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * n), $MachinePrecision] / k), $MachinePrecision], N[(N[Sqrt[N[(N[(Pi + Pi), $MachinePrecision] / N[(k * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * n), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq 8 \cdot 10^{-43}:\\
\;\;\;\;\frac{\sqrt{\frac{\pi \cdot k}{n} \cdot 2} \cdot n}{k}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < 8.00000000000000062e-43

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      2. metadata-evalN/A

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

        \[\leadsto \frac{\sqrt{1}}{\color{blue}{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      4. sqrt-divN/A

        \[\leadsto \color{blue}{\sqrt{\frac{1}{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \color{blue}{\sqrt{\frac{1}{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
      6. lower-/.f6499.4

        \[\leadsto \sqrt{\color{blue}{\frac{1}{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    3. Applied rewrites99.4%

      \[\leadsto \color{blue}{\sqrt{\frac{1}{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    4. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{\sqrt{k} \cdot {\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{k}} \]
    5. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\sqrt{k} \cdot {\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{k}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}} \cdot \sqrt{k}}{k} \]
      3. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)} \cdot \sqrt{k}}{k} \]
      4. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)} \cdot \sqrt{k}}{k} \]
      5. associate-*l*N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n} \cdot \sqrt{k}}{k} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n} \cdot \sqrt{k}}{k} \]
      7. count-2-revN/A

        \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n} \cdot \sqrt{k}}{k} \]
      8. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n} \cdot \sqrt{k}}{k} \]
      9. lift-PI.f64N/A

        \[\leadsto \frac{\sqrt{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n} \cdot \sqrt{k}}{k} \]
      10. lift-PI.f64N/A

        \[\leadsto \frac{\sqrt{\left(\pi + \pi\right) \cdot n} \cdot \sqrt{k}}{k} \]
      11. sqrt-unprodN/A

        \[\leadsto \frac{\sqrt{\left(\left(\pi + \pi\right) \cdot n\right) \cdot k}}{k} \]
      12. lower-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{\left(\left(\pi + \pi\right) \cdot n\right) \cdot k}}{k} \]
      13. lower-*.f6438.3

        \[\leadsto \frac{\sqrt{\left(\left(\pi + \pi\right) \cdot n\right) \cdot k}}{k} \]
    6. Applied rewrites38.3%

      \[\leadsto \color{blue}{\frac{\sqrt{\left(\left(\pi + \pi\right) \cdot n\right) \cdot k}}{k}} \]
    7. Taylor expanded in n around inf

      \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{k \cdot \mathsf{PI}\left(\right)}{n}}}{k} \]
    8. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \frac{k \cdot \mathsf{PI}\left(\right)}{n}} \cdot n}{k} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \frac{k \cdot \mathsf{PI}\left(\right)}{n}} \cdot n}{k} \]
      3. lower-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \frac{k \cdot \mathsf{PI}\left(\right)}{n}} \cdot n}{k} \]
      4. *-commutativeN/A

        \[\leadsto \frac{\sqrt{\frac{k \cdot \mathsf{PI}\left(\right)}{n} \cdot 2} \cdot n}{k} \]
      5. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{\frac{k \cdot \mathsf{PI}\left(\right)}{n} \cdot 2} \cdot n}{k} \]
      6. lower-/.f64N/A

        \[\leadsto \frac{\sqrt{\frac{k \cdot \mathsf{PI}\left(\right)}{n} \cdot 2} \cdot n}{k} \]
      7. *-commutativeN/A

        \[\leadsto \frac{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot k}{n} \cdot 2} \cdot n}{k} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot k}{n} \cdot 2} \cdot n}{k} \]
      9. lift-PI.f6451.5

        \[\leadsto \frac{\sqrt{\frac{\pi \cdot k}{n} \cdot 2} \cdot n}{k} \]
    9. Applied rewrites51.5%

      \[\leadsto \frac{\sqrt{\frac{\pi \cdot k}{n} \cdot 2} \cdot n}{k} \]

    if 8.00000000000000062e-43 < n

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{\color{blue}{k}}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
      3. associate-*l*N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      4. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      6. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      7. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      8. count-2-revN/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      9. lower-+.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      10. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      11. lift-PI.f6438.3

        \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
    4. Applied rewrites38.3%

      \[\leadsto \color{blue}{\sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}}} \]
    5. Taylor expanded in n around inf

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}}} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      3. lower-sqrt.f64N/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      4. associate-*r/N/A

        \[\leadsto \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      5. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      6. count-2-revN/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      7. lift-+.f64N/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      8. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\pi + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      9. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n \]
      10. lower-*.f6449.7

        \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n \]
    7. Applied rewrites49.7%

      \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot \color{blue}{n} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 61.9% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq 5000:\\ \;\;\;\;\sqrt{\frac{\pi \cdot n}{k} \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n\\ \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= n 5000.0)
   (sqrt (* (/ (* PI n) k) 2.0))
   (* (sqrt (/ (+ PI PI) (* k n))) n)))
double code(double k, double n) {
	double tmp;
	if (n <= 5000.0) {
		tmp = sqrt((((((double) M_PI) * n) / k) * 2.0));
	} else {
		tmp = sqrt(((((double) M_PI) + ((double) M_PI)) / (k * n))) * n;
	}
	return tmp;
}
public static double code(double k, double n) {
	double tmp;
	if (n <= 5000.0) {
		tmp = Math.sqrt((((Math.PI * n) / k) * 2.0));
	} else {
		tmp = Math.sqrt(((Math.PI + Math.PI) / (k * n))) * n;
	}
	return tmp;
}
def code(k, n):
	tmp = 0
	if n <= 5000.0:
		tmp = math.sqrt((((math.pi * n) / k) * 2.0))
	else:
		tmp = math.sqrt(((math.pi + math.pi) / (k * n))) * n
	return tmp
function code(k, n)
	tmp = 0.0
	if (n <= 5000.0)
		tmp = sqrt(Float64(Float64(Float64(pi * n) / k) * 2.0));
	else
		tmp = Float64(sqrt(Float64(Float64(pi + pi) / Float64(k * n))) * n);
	end
	return tmp
end
function tmp_2 = code(k, n)
	tmp = 0.0;
	if (n <= 5000.0)
		tmp = sqrt((((pi * n) / k) * 2.0));
	else
		tmp = sqrt(((pi + pi) / (k * n))) * n;
	end
	tmp_2 = tmp;
end
code[k_, n_] := If[LessEqual[n, 5000.0], N[Sqrt[N[(N[(N[(Pi * n), $MachinePrecision] / k), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], N[(N[Sqrt[N[(N[(Pi + Pi), $MachinePrecision] / N[(k * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * n), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n \leq 5000:\\
\;\;\;\;\sqrt{\frac{\pi \cdot n}{k} \cdot 2}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < 5e3

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{\color{blue}{k}}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
      3. associate-*l*N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      4. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      6. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      7. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      8. count-2-revN/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      9. lower-+.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      10. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      11. lift-PI.f6438.3

        \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
    4. Applied rewrites38.3%

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

        \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
      2. lift-*.f64N/A

        \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
      3. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \pi\right) \cdot n}{k}} \]
      4. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      5. lift-+.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      6. count-2-revN/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      7. associate-*l*N/A

        \[\leadsto \sqrt{\frac{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}{k}} \]
      8. *-commutativeN/A

        \[\leadsto \sqrt{\frac{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}{k}} \]
      9. associate-*r/N/A

        \[\leadsto \sqrt{2 \cdot \frac{n \cdot \mathsf{PI}\left(\right)}{k}} \]
      10. *-commutativeN/A

        \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
      11. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
      12. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
      13. *-commutativeN/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2} \]
      14. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2} \]
      15. lift-PI.f6438.3

        \[\leadsto \sqrt{\frac{\pi \cdot n}{k} \cdot 2} \]
    6. Applied rewrites38.3%

      \[\leadsto \sqrt{\frac{\pi \cdot n}{k} \cdot 2} \]

    if 5e3 < n

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{\color{blue}{k}}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
      3. associate-*l*N/A

        \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
      4. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      6. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      7. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      8. count-2-revN/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      9. lower-+.f64N/A

        \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      10. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
      11. lift-PI.f6438.3

        \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
    4. Applied rewrites38.3%

      \[\leadsto \color{blue}{\sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}}} \]
    5. Taylor expanded in n around inf

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}}} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      3. lower-sqrt.f64N/A

        \[\leadsto \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      4. associate-*r/N/A

        \[\leadsto \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      5. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      6. count-2-revN/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      7. lift-+.f64N/A

        \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      8. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\pi + \mathsf{PI}\left(\right)}{k \cdot n}} \cdot n \]
      9. lift-PI.f64N/A

        \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n \]
      10. lower-*.f6449.7

        \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot n \]
    7. Applied rewrites49.7%

      \[\leadsto \sqrt{\frac{\pi + \pi}{k \cdot n}} \cdot \color{blue}{n} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 6: 49.9% accurate, 2.7× speedup?

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

\\
\frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}} \]
    2. lift-/.f64N/A

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

      \[\leadsto \frac{1}{\color{blue}{\sqrt{k}}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    4. lift-pow.f64N/A

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\color{blue}{\left(\left(2 \cdot \pi\right) \cdot n\right)}}^{\left(\frac{1 - k}{2}\right)} \]
    6. lift-PI.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\color{blue}{\left(2 \cdot \mathsf{PI}\left(\right)\right)} \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    8. lift--.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{\color{blue}{1 - k}}{2}\right)} \]
    9. lift-/.f64N/A

      \[\leadsto \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\color{blue}{\left(\frac{1 - k}{2}\right)}} \]
    10. *-commutativeN/A

      \[\leadsto \color{blue}{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \frac{1}{\sqrt{k}}} \]
    11. mult-flip-revN/A

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
    12. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
  3. Applied rewrites99.5%

    \[\leadsto \color{blue}{\frac{{\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}} \]
  4. Taylor expanded in k around 0

    \[\leadsto \frac{\color{blue}{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}}{\sqrt{k}} \]
  5. Step-by-step derivation
    1. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{k}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
    3. associate-*l*N/A

      \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    5. count-2-revN/A

      \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    6. lift-+.f64N/A

      \[\leadsto \frac{\sqrt{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    7. lift-PI.f64N/A

      \[\leadsto \frac{\sqrt{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    8. lift-PI.f64N/A

      \[\leadsto \frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}} \]
    9. lower-sqrt.f6449.9

      \[\leadsto \frac{\sqrt{\left(\pi + \pi\right) \cdot n}}{\sqrt{k}} \]
  6. Applied rewrites49.9%

    \[\leadsto \frac{\color{blue}{\sqrt{\left(\pi + \pi\right) \cdot n}}}{\sqrt{k}} \]
  7. Add Preprocessing

Alternative 7: 38.3% accurate, 3.1× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{\pi \cdot n}{k} \cdot 2} \end{array} \]
(FPCore (k n) :precision binary64 (sqrt (* (/ (* PI n) k) 2.0)))
double code(double k, double n) {
	return sqrt((((((double) M_PI) * n) / k) * 2.0));
}
public static double code(double k, double n) {
	return Math.sqrt((((Math.PI * n) / k) * 2.0));
}
def code(k, n):
	return math.sqrt((((math.pi * n) / k) * 2.0))
function code(k, n)
	return sqrt(Float64(Float64(Float64(pi * n) / k) * 2.0))
end
function tmp = code(k, n)
	tmp = sqrt((((pi * n) / k) * 2.0));
end
code[k_, n_] := N[Sqrt[N[(N[(N[(Pi * n), $MachinePrecision] / k), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{\pi \cdot n}{k} \cdot 2}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{\color{blue}{k}}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
    3. associate-*l*N/A

      \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    4. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    5. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    6. lower-/.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    7. lower-*.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    8. count-2-revN/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    9. lower-+.f64N/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    10. lift-PI.f64N/A

      \[\leadsto \sqrt{\frac{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    11. lift-PI.f6438.3

      \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
  4. Applied rewrites38.3%

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

      \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
    2. lift-*.f64N/A

      \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
    3. lift-PI.f64N/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \pi\right) \cdot n}{k}} \]
    4. lift-PI.f64N/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    5. lift-+.f64N/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    6. count-2-revN/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    7. associate-*l*N/A

      \[\leadsto \sqrt{\frac{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}{k}} \]
    8. *-commutativeN/A

      \[\leadsto \sqrt{\frac{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}{k}} \]
    9. associate-*r/N/A

      \[\leadsto \sqrt{2 \cdot \frac{n \cdot \mathsf{PI}\left(\right)}{k}} \]
    10. *-commutativeN/A

      \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
    11. lower-*.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
    12. lower-/.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \mathsf{PI}\left(\right)}{k} \cdot 2} \]
    13. *-commutativeN/A

      \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2} \]
    14. lower-*.f64N/A

      \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2} \]
    15. lift-PI.f6438.3

      \[\leadsto \sqrt{\frac{\pi \cdot n}{k} \cdot 2} \]
  6. Applied rewrites38.3%

    \[\leadsto \sqrt{\frac{\pi \cdot n}{k} \cdot 2} \]
  7. Add Preprocessing

Alternative 8: 38.3% accurate, 3.1× speedup?

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

\\
\sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\sqrt{\color{blue}{k}}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}}{\sqrt{k}} \]
    3. associate-*l*N/A

      \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k}} \]
    4. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    5. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    6. lower-/.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    7. lower-*.f64N/A

      \[\leadsto \sqrt{\frac{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    8. count-2-revN/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    9. lower-+.f64N/A

      \[\leadsto \sqrt{\frac{\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    10. lift-PI.f64N/A

      \[\leadsto \sqrt{\frac{\left(\pi + \mathsf{PI}\left(\right)\right) \cdot n}{k}} \]
    11. lift-PI.f6438.3

      \[\leadsto \sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}} \]
  4. Applied rewrites38.3%

    \[\leadsto \color{blue}{\sqrt{\frac{\left(\pi + \pi\right) \cdot n}{k}}} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2025140 
(FPCore (k n)
  :name "Migdal et al, Equation (51)"
  :precision binary64
  (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))