Migdal et al, Equation (51)

Percentage Accurate: 99.4% → 99.5%
Time: 10.6s
Alternatives: 12
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \end{array} \]
(FPCore (k n)
 :precision binary64
 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 (PI)) n) (/ (- 1.0 k) 2.0))))
\begin{array}{l}

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 12 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?

\[\begin{array}{l} \\ \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \end{array} \]
(FPCore (k n)
 :precision binary64
 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 (PI)) n) (/ (- 1.0 k) 2.0))))
\begin{array}{l}

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

Alternative 1: 99.5% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\ \frac{\sqrt{t\_0}}{{\left({t\_0}^{k}\right)}^{0.5} \cdot \sqrt{k}} \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (let* ((t_0 (* (* 2.0 (PI)) n)))
   (/ (sqrt t_0) (* (pow (pow t_0 k) 0.5) (sqrt k)))))
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\
\frac{\sqrt{t\_0}}{{\left({t\_0}^{k}\right)}^{0.5} \cdot \sqrt{k}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.4%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\frac{1}{2}}}{\sqrt{k} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{k}{2}\right)}}} \]
  4. Applied rewrites99.7%

    \[\leadsto \color{blue}{\frac{\sqrt{n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)}}{\sqrt{k} \cdot {\left({\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{k}\right)}^{0.5}}} \]
  5. Final simplification99.7%

    \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{{\left({\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{k}\right)}^{0.5} \cdot \sqrt{k}} \]
  6. Add Preprocessing

Alternative 2: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\ \frac{\sqrt{t\_0}}{\sqrt{{t\_0}^{k} \cdot k}} \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (let* ((t_0 (* (* 2.0 (PI)) n))) (/ (sqrt t_0) (sqrt (* (pow t_0 k) k)))))
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\
\frac{\sqrt{t\_0}}{\sqrt{{t\_0}^{k} \cdot k}}
\end{array}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \color{blue}{\sqrt{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}} \]
    8. lower-pow.f6499.4

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\color{blue}{\left(n \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right)\right)}}^{\left(1 - k\right)}} \]
    11. lower-*.f6499.4

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\left(n \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot 2\right)}\right)}^{\left(1 - k\right)}} \]
    14. lower-*.f6499.4

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

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

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

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

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

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

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

      \[\leadsto \frac{\sqrt{\color{blue}{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(1 - k\right)}}}}{\sqrt{k}} \]
    7. sqrt-pow1N/A

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

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

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

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

      \[\leadsto \frac{\color{blue}{\frac{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\frac{1}{2}}}{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(\frac{k}{2}\right)}}}}{\sqrt{k}} \]
    12. pow1/2N/A

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

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

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

      \[\leadsto \color{blue}{\frac{\frac{\sqrt{n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)}}{\sqrt{k}}}{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(\frac{k}{2}\right)}}} \]
  6. Applied rewrites99.7%

    \[\leadsto \color{blue}{\frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{k \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{k}}}} \]
  7. Final simplification99.7%

    \[\leadsto \frac{\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}}{\sqrt{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{k} \cdot k}} \]
  8. Add Preprocessing

Alternative 3: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{{\left(\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}\right)}^{\left(1 - k\right)}}{\sqrt{k}} \end{array} \]
(FPCore (k n)
 :precision binary64
 (/ (pow (sqrt (* (* 2.0 (PI)) n)) (- 1.0 k)) (sqrt k)))
\begin{array}{l}

\\
\frac{{\left(\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}\right)}^{\left(1 - k\right)}}{\sqrt{k}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \color{blue}{\sqrt{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}} \]
    8. lower-pow.f6499.4

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\color{blue}{\left(n \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right)\right)}}^{\left(1 - k\right)}} \]
    11. lower-*.f6499.4

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

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

      \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\left(n \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot 2\right)}\right)}^{\left(1 - k\right)}} \]
    14. lower-*.f6499.4

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

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

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

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

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

      \[\leadsto \color{blue}{\frac{\sqrt{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(1 - k\right)}}}{\sqrt{k}}} \]
    5. lower-/.f6499.5

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

    \[\leadsto \color{blue}{\frac{{\left(\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}\right)}^{\left(1 - k\right)}}{\sqrt{k}}} \]
  7. Add Preprocessing

Alternative 4: 99.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;k \leq 2.5 \cdot 10^{-15}:\\ \;\;\;\;\sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}{k}}\\ \end{array} \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= k 2.5e-15)
   (* (sqrt (* 2.0 n)) (sqrt (/ (PI) k)))
   (sqrt (/ (pow (* (* 2.0 (PI)) n) (- 1.0 k)) k))))
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;k \leq 2.5 \cdot 10^{-15}:\\
\;\;\;\;\sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}{k}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if k < 2.5e-15

    1. Initial program 99.1%

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

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

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

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

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

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

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

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

        \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
      8. lower-PI.f6473.3

        \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
    5. Applied rewrites73.3%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
    6. Step-by-step derivation
      1. Applied rewrites72.8%

        \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
      2. Step-by-step derivation
        1. Applied rewrites72.9%

          \[\leadsto \sqrt{\left(n \cdot \frac{\mathsf{PI}\left(\right)}{k}\right) \cdot 2} \]
        2. Step-by-step derivation
          1. Applied rewrites99.1%

            \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right)}{k}} \cdot \color{blue}{\sqrt{n \cdot 2}} \]

          if 2.5e-15 < k

          1. Initial program 99.8%

            \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift-pow.f64N/A

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

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

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

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

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

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

              \[\leadsto \frac{1}{\sqrt{k}} \cdot \color{blue}{\sqrt{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}} \]
            8. lower-pow.f6499.8

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

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

              \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\color{blue}{\left(n \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right)\right)}}^{\left(1 - k\right)}} \]
            11. lower-*.f6499.8

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

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

              \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\left(n \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot 2\right)}\right)}^{\left(1 - k\right)}} \]
            14. lower-*.f6499.8

              \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\left(n \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot 2\right)}\right)}^{\left(1 - k\right)}} \]
          4. Applied rewrites99.8%

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

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

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

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

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

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

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

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

              \[\leadsto \color{blue}{\sqrt{\frac{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(1 - k\right)}}{k}}} \]
            9. lower-/.f6499.8

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

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

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

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

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

              \[\leadsto \sqrt{\frac{{\color{blue}{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}}^{\left(1 - k\right)}}{k}} \]
            15. lift-*.f6499.8

              \[\leadsto \sqrt{\frac{{\color{blue}{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}}^{\left(1 - k\right)}}{k}} \]
          6. Applied rewrites99.8%

            \[\leadsto \color{blue}{\sqrt{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}{k}}} \]
        3. Recombined 2 regimes into one program.
        4. Final simplification99.4%

          \[\leadsto \begin{array}{l} \mathbf{if}\;k \leq 2.5 \cdot 10^{-15}:\\ \;\;\;\;\sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}{k}}\\ \end{array} \]
        5. Add Preprocessing

        Alternative 5: 99.5% accurate, 1.1× speedup?

        \[\begin{array}{l} \\ \frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\left(1 - k\right) \cdot 0.5\right)}}{\sqrt{k}} \end{array} \]
        (FPCore (k n)
         :precision binary64
         (/ (pow (* (* 2.0 (PI)) n) (* (- 1.0 k) 0.5)) (sqrt k)))
        \begin{array}{l}
        
        \\
        \frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\left(1 - k\right) \cdot 0.5\right)}}{\sqrt{k}}
        \end{array}
        
        Derivation
        1. Initial program 99.4%

          \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-pow.f64N/A

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

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

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

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

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

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

            \[\leadsto \frac{1}{\sqrt{k}} \cdot \color{blue}{\sqrt{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(1 - k\right)}}} \]
          8. lower-pow.f6499.4

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

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

            \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\color{blue}{\left(n \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right)\right)}}^{\left(1 - k\right)}} \]
          11. lower-*.f6499.4

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

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

            \[\leadsto \frac{1}{\sqrt{k}} \cdot \sqrt{{\left(n \cdot \color{blue}{\left(\mathsf{PI}\left(\right) \cdot 2\right)}\right)}^{\left(1 - k\right)}} \]
          14. lower-*.f6499.4

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

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

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

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

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

            \[\leadsto \color{blue}{\frac{\sqrt{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(1 - k\right)}}}{\sqrt{k}}} \]
          5. lower-/.f6499.5

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

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

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

            \[\leadsto \frac{{\color{blue}{\left(\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}\right)}}^{\left(1 - k\right)}}{\sqrt{k}} \]
          3. sqrt-pow2N/A

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(\color{blue}{\frac{1}{2}} \cdot \left(1 - k\right)\right)}}{\sqrt{k}} \]
          16. lower-*.f6499.5

            \[\leadsto \frac{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\color{blue}{\left(0.5 \cdot \left(1 - k\right)\right)}}}{\sqrt{k}} \]
        8. Applied rewrites99.5%

          \[\leadsto \frac{\color{blue}{{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right)}^{\left(0.5 \cdot \left(1 - k\right)\right)}}}{\sqrt{k}} \]
        9. Final simplification99.5%

          \[\leadsto \frac{{\left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}^{\left(\left(1 - k\right) \cdot 0.5\right)}}{\sqrt{k}} \]
        10. Add Preprocessing

        Alternative 6: 62.5% accurate, 2.3× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\ \mathbf{if}\;t\_0 \leq 5 \cdot 10^{+16}:\\ \;\;\;\;\sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(--2\right) \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}{\sqrt{k \cdot t\_0}}\\ \end{array} \end{array} \]
        (FPCore (k n)
         :precision binary64
         (let* ((t_0 (* (* 2.0 (PI)) n)))
           (if (<= t_0 5e+16)
             (sqrt (* (* (/ (PI) k) n) 2.0))
             (/ (* (- -2.0) (* (PI) n)) (sqrt (* k t_0))))))
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\\
        \mathbf{if}\;t\_0 \leq 5 \cdot 10^{+16}:\\
        \;\;\;\;\sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2}\\
        
        \mathbf{else}:\\
        \;\;\;\;\frac{\left(--2\right) \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}{\sqrt{k \cdot t\_0}}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) < 5e16

          1. Initial program 99.5%

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

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

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

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

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

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

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

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

              \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
            8. lower-PI.f6448.7

              \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
          5. Applied rewrites48.7%

            \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
          6. Step-by-step derivation
            1. Applied rewrites48.9%

              \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
            2. Step-by-step derivation
              1. Applied rewrites49.0%

                \[\leadsto \sqrt{\left(n \cdot \frac{\mathsf{PI}\left(\right)}{k}\right) \cdot 2} \]

              if 5e16 < (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n)

              1. Initial program 99.4%

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

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

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

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

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

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

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

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

                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                8. lower-PI.f6421.4

                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
              5. Applied rewrites21.4%

                \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
              6. Step-by-step derivation
                1. Applied rewrites50.6%

                  \[\leadsto \left(-\sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n}\right) \cdot \color{blue}{\frac{-1}{\sqrt{k}}} \]
                2. Step-by-step derivation
                  1. Applied rewrites50.6%

                    \[\leadsto \frac{1}{\frac{\sqrt{n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)}}{-2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}} \cdot \frac{\color{blue}{-1}}{\sqrt{k}} \]
                  2. Step-by-step derivation
                    1. Applied rewrites78.5%

                      \[\leadsto \frac{\left(-2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right) \cdot -1}{\color{blue}{\sqrt{\left(n \cdot \left(\mathsf{PI}\left(\right) \cdot 2\right)\right) \cdot k}}} \]
                  3. Recombined 2 regimes into one program.
                  4. Final simplification61.4%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n \leq 5 \cdot 10^{+16}:\\ \;\;\;\;\sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(--2\right) \cdot \left(\mathsf{PI}\left(\right) \cdot n\right)}{\sqrt{k \cdot \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot n\right)}}\\ \end{array} \]
                  5. Add Preprocessing

                  Alternative 7: 49.8% accurate, 3.6× speedup?

                  \[\begin{array}{l} \\ \sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}} \end{array} \]
                  (FPCore (k n) :precision binary64 (* (sqrt (* 2.0 n)) (sqrt (/ (PI) k))))
                  \begin{array}{l}
                  
                  \\
                  \sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}}
                  \end{array}
                  
                  Derivation
                  1. Initial program 99.4%

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

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

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

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

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

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

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

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

                      \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                    8. lower-PI.f6437.2

                      \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                  5. Applied rewrites37.2%

                    \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                  6. Step-by-step derivation
                    1. Applied rewrites37.0%

                      \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
                    2. Step-by-step derivation
                      1. Applied rewrites37.0%

                        \[\leadsto \sqrt{\left(n \cdot \frac{\mathsf{PI}\left(\right)}{k}\right) \cdot 2} \]
                      2. Step-by-step derivation
                        1. Applied rewrites49.7%

                          \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right)}{k}} \cdot \color{blue}{\sqrt{n \cdot 2}} \]
                        2. Final simplification49.7%

                          \[\leadsto \sqrt{2 \cdot n} \cdot \sqrt{\frac{\mathsf{PI}\left(\right)}{k}} \]
                        3. Add Preprocessing

                        Alternative 8: 49.8% accurate, 3.6× speedup?

                        \[\begin{array}{l} \\ \sqrt{\mathsf{PI}\left(\right) \cdot n} \cdot \sqrt{\frac{2}{k}} \end{array} \]
                        (FPCore (k n) :precision binary64 (* (sqrt (* (PI) n)) (sqrt (/ 2.0 k))))
                        \begin{array}{l}
                        
                        \\
                        \sqrt{\mathsf{PI}\left(\right) \cdot n} \cdot \sqrt{\frac{2}{k}}
                        \end{array}
                        
                        Derivation
                        1. Initial program 99.4%

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

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

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

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

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

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

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

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

                            \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                          8. lower-PI.f6437.2

                            \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                        5. Applied rewrites37.2%

                          \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                        6. Step-by-step derivation
                          1. Applied rewrites37.0%

                            \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
                          2. Step-by-step derivation
                            1. Applied rewrites49.7%

                              \[\leadsto \sqrt{\frac{2}{k}} \cdot \color{blue}{\sqrt{n \cdot \mathsf{PI}\left(\right)}} \]
                            2. Final simplification49.7%

                              \[\leadsto \sqrt{\mathsf{PI}\left(\right) \cdot n} \cdot \sqrt{\frac{2}{k}} \]
                            3. Add Preprocessing

                            Alternative 9: 49.8% accurate, 3.6× speedup?

                            \[\begin{array}{l} \\ \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k}} \cdot \sqrt{n} \end{array} \]
                            (FPCore (k n) :precision binary64 (* (sqrt (/ (* 2.0 (PI)) k)) (sqrt n)))
                            \begin{array}{l}
                            
                            \\
                            \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k}} \cdot \sqrt{n}
                            \end{array}
                            
                            Derivation
                            1. Initial program 99.4%

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

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

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

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

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

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

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

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

                                \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                              8. lower-PI.f6437.2

                                \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                            5. Applied rewrites37.2%

                              \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                            6. Step-by-step derivation
                              1. Applied rewrites49.6%

                                \[\leadsto \sqrt{n} \cdot \color{blue}{\sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k}}} \]
                              2. Final simplification49.6%

                                \[\leadsto \sqrt{\frac{2 \cdot \mathsf{PI}\left(\right)}{k}} \cdot \sqrt{n} \]
                              3. Add Preprocessing

                              Alternative 10: 37.7% accurate, 3.6× speedup?

                              \[\begin{array}{l} \\ \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}} \cdot \sqrt{2} \end{array} \]
                              (FPCore (k n) :precision binary64 (* (sqrt (/ (* (PI) n) k)) (sqrt 2.0)))
                              \begin{array}{l}
                              
                              \\
                              \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}} \cdot \sqrt{2}
                              \end{array}
                              
                              Derivation
                              1. Initial program 99.4%

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

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

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

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

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

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

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

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

                                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                                8. lower-PI.f6437.2

                                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                              5. Applied rewrites37.2%

                                \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                              6. Final simplification37.2%

                                \[\leadsto \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}} \cdot \sqrt{2} \]
                              7. Add Preprocessing

                              Alternative 11: 37.8% accurate, 4.0× speedup?

                              \[\begin{array}{l} \\ \sqrt{\frac{2 \cdot n}{\frac{k}{\mathsf{PI}\left(\right)}}} \end{array} \]
                              (FPCore (k n) :precision binary64 (sqrt (/ (* 2.0 n) (/ k (PI)))))
                              \begin{array}{l}
                              
                              \\
                              \sqrt{\frac{2 \cdot n}{\frac{k}{\mathsf{PI}\left(\right)}}}
                              \end{array}
                              
                              Derivation
                              1. Initial program 99.4%

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

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

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

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

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

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

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

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

                                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                                8. lower-PI.f6437.2

                                  \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                              5. Applied rewrites37.2%

                                \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                              6. Step-by-step derivation
                                1. Applied rewrites37.0%

                                  \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
                                2. Step-by-step derivation
                                  1. Applied rewrites37.0%

                                    \[\leadsto \sqrt{\left(n \cdot \frac{\mathsf{PI}\left(\right)}{k}\right) \cdot 2} \]
                                  2. Step-by-step derivation
                                    1. Applied rewrites37.0%

                                      \[\leadsto \sqrt{\frac{2 \cdot n}{\frac{k}{\mathsf{PI}\left(\right)}}} \]
                                    2. Add Preprocessing

                                    Alternative 12: 37.8% accurate, 4.8× speedup?

                                    \[\begin{array}{l} \\ \sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2} \end{array} \]
                                    (FPCore (k n) :precision binary64 (sqrt (* (* (/ (PI) k) n) 2.0)))
                                    \begin{array}{l}
                                    
                                    \\
                                    \sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2}
                                    \end{array}
                                    
                                    Derivation
                                    1. Initial program 99.4%

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

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

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

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

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

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

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

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

                                        \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right) \cdot n}}{k}} \]
                                      8. lower-PI.f6437.2

                                        \[\leadsto \sqrt{2} \cdot \sqrt{\frac{\color{blue}{\mathsf{PI}\left(\right)} \cdot n}{k}} \]
                                    5. Applied rewrites37.2%

                                      \[\leadsto \color{blue}{\sqrt{2} \cdot \sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k}}} \]
                                    6. Step-by-step derivation
                                      1. Applied rewrites37.0%

                                        \[\leadsto \color{blue}{\sqrt{\frac{\mathsf{PI}\left(\right) \cdot n}{k} \cdot 2}} \]
                                      2. Step-by-step derivation
                                        1. Applied rewrites37.0%

                                          \[\leadsto \sqrt{\left(n \cdot \frac{\mathsf{PI}\left(\right)}{k}\right) \cdot 2} \]
                                        2. Final simplification37.0%

                                          \[\leadsto \sqrt{\left(\frac{\mathsf{PI}\left(\right)}{k} \cdot n\right) \cdot 2} \]
                                        3. Add Preprocessing

                                        Reproduce

                                        ?
                                        herbie shell --seed 2024271 
                                        (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))))