2cbrt (problem 3.3.4)

Percentage Accurate: 7.0% → 98.4%
Time: 4.8s
Alternatives: 10
Speedup: 1.9×

Specification

?
\[x > 1 \land x < 10^{+308}\]
\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\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 10 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: 7.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}

Alternative 1: 98.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{x - -1}\\ \mathbf{if}\;x \leq 8.2 \cdot 10^{+14}:\\ \;\;\;\;\frac{\left(x - -1\right) - x}{{t\_0}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + t\_0\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (- x -1.0))))
   (if (<= x 8.2e+14)
     (/ (- (- x -1.0) x) (+ (pow t_0 2.0) (* (cbrt x) (+ (cbrt x) t_0))))
     (/ (* (pow (cbrt x) -1.0) -0.3333333333333333) (- (cbrt x))))))
double code(double x) {
	double t_0 = cbrt((x - -1.0));
	double tmp;
	if (x <= 8.2e+14) {
		tmp = ((x - -1.0) - x) / (pow(t_0, 2.0) + (cbrt(x) * (cbrt(x) + t_0)));
	} else {
		tmp = (pow(cbrt(x), -1.0) * -0.3333333333333333) / -cbrt(x);
	}
	return tmp;
}
public static double code(double x) {
	double t_0 = Math.cbrt((x - -1.0));
	double tmp;
	if (x <= 8.2e+14) {
		tmp = ((x - -1.0) - x) / (Math.pow(t_0, 2.0) + (Math.cbrt(x) * (Math.cbrt(x) + t_0)));
	} else {
		tmp = (Math.pow(Math.cbrt(x), -1.0) * -0.3333333333333333) / -Math.cbrt(x);
	}
	return tmp;
}
function code(x)
	t_0 = cbrt(Float64(x - -1.0))
	tmp = 0.0
	if (x <= 8.2e+14)
		tmp = Float64(Float64(Float64(x - -1.0) - x) / Float64((t_0 ^ 2.0) + Float64(cbrt(x) * Float64(cbrt(x) + t_0))));
	else
		tmp = Float64(Float64((cbrt(x) ^ -1.0) * -0.3333333333333333) / Float64(-cbrt(x)));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Power[N[(x - -1.0), $MachinePrecision], 1/3], $MachinePrecision]}, If[LessEqual[x, 8.2e+14], N[(N[(N[(x - -1.0), $MachinePrecision] - x), $MachinePrecision] / N[(N[Power[t$95$0, 2.0], $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[(N[Power[x, 1/3], $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Power[N[Power[x, 1/3], $MachinePrecision], -1.0], $MachinePrecision] * -0.3333333333333333), $MachinePrecision] / (-N[Power[x, 1/3], $MachinePrecision])), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{x - -1}\\
\mathbf{if}\;x \leq 8.2 \cdot 10^{+14}:\\
\;\;\;\;\frac{\left(x - -1\right) - x}{{t\_0}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + t\_0\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 8.2e14

    1. Initial program 54.8%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \color{blue}{\sqrt[3]{x + 1} - \sqrt[3]{x}} \]
      2. lift-+.f64N/A

        \[\leadsto \sqrt[3]{\color{blue}{x + 1}} - \sqrt[3]{x} \]
      3. lift-cbrt.f64N/A

        \[\leadsto \color{blue}{\sqrt[3]{x + 1}} - \sqrt[3]{x} \]
      4. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{x + 1} - \color{blue}{\sqrt[3]{x}} \]
      5. flip3--N/A

        \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      6. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
      7. rem-cube-cbrtN/A

        \[\leadsto \frac{\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      8. rem-cube-cbrtN/A

        \[\leadsto \frac{\left(x + 1\right) - \color{blue}{x}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      9. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\left(x + 1\right) - x}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      10. metadata-evalN/A

        \[\leadsto \frac{\left(x + \color{blue}{1 \cdot 1}\right) - x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      11. fp-cancel-sign-sub-invN/A

        \[\leadsto \frac{\color{blue}{\left(x - \left(\mathsf{neg}\left(1\right)\right) \cdot 1\right)} - x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      12. metadata-evalN/A

        \[\leadsto \frac{\left(x - \color{blue}{-1} \cdot 1\right) - x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      13. metadata-evalN/A

        \[\leadsto \frac{\left(x - \color{blue}{-1}\right) - x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      14. lower--.f64N/A

        \[\leadsto \frac{\color{blue}{\left(x - -1\right)} - x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
      15. lower-+.f64N/A

        \[\leadsto \frac{\left(x - -1\right) - x}{\color{blue}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
    4. Applied rewrites98.6%

      \[\leadsto \color{blue}{\frac{\left(x - -1\right) - x}{{\left(\sqrt[3]{x - -1}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x - -1}\right)}} \]

    if 8.2e14 < x

    1. Initial program 4.3%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval49.0

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites49.0%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      10. pow2N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      11. lower-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      12. lift-cbrt.f6498.3

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    7. Applied rewrites98.3%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. pow1/398.3

        \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}} \cdot 0.3333333333333333 \]
      2. lift-/.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      3. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      5. pow-flipN/A

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{\left(\mathsf{neg}\left(2\right)\right)} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
      7. lower-pow.f64N/A

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
      8. lift-cbrt.f6498.3

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333 \]
    9. Applied rewrites98.3%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

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

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
      3. lift-pow.f64N/A

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
      4. metadata-evalN/A

        \[\leadsto {\left(\sqrt[3]{x}\right)}^{\left(2 \cdot -1\right)} \cdot \frac{1}{3} \]
      5. pow-sqrN/A

        \[\leadsto \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3} \]
      6. inv-powN/A

        \[\leadsto \left(\frac{1}{\sqrt[3]{x}} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3} \]
      7. inv-powN/A

        \[\leadsto \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right) \cdot \frac{1}{3} \]
      8. associate-*l*N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{3}\right)} \]
      9. associate-*l/N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{1 \cdot \frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
      10. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{\color{blue}{x}}} \]
      11. frac-2negN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\color{blue}{\mathsf{neg}\left(\sqrt[3]{x}\right)}} \]
      12. pow1/3N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\mathsf{neg}\left({x}^{\frac{1}{3}}\right)} \]
      13. sqr-powN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)} \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)} \]
      14. distribute-lft-neg-inN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot \color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
      15. associate-*r/N/A

        \[\leadsto \frac{\frac{1}{\sqrt[3]{x}} \cdot \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)}{\color{blue}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
      16. lower-/.f64N/A

        \[\leadsto \frac{\frac{1}{\sqrt[3]{x}} \cdot \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)}{\color{blue}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
    11. Applied rewrites98.3%

      \[\leadsto \frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{\color{blue}{-\sqrt[3]{x}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 8.2 \cdot 10^{+14}:\\ \;\;\;\;\frac{\left(x - -1\right) - x}{{\left(\sqrt[3]{x - -1}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x - -1}\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 97.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 5 \cdot 10^{+76}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\sqrt[3]{{x}^{-2}}, 0.06172839506172839, \mathsf{fma}\left(\sqrt[3]{{x}^{4}}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)\right)}{x \cdot x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot 0.3333333333333333\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 5e+76)
   (/
    (fma
     (cbrt (pow x -2.0))
     0.06172839506172839
     (fma
      (cbrt (pow x 4.0))
      0.3333333333333333
      (* -0.1111111111111111 (cbrt x))))
    (* x x))
   (* (/ 1.0 (cbrt x)) (* (pow (cbrt x) -1.0) 0.3333333333333333))))
double code(double x) {
	double tmp;
	if (x <= 5e+76) {
		tmp = fma(cbrt(pow(x, -2.0)), 0.06172839506172839, fma(cbrt(pow(x, 4.0)), 0.3333333333333333, (-0.1111111111111111 * cbrt(x)))) / (x * x);
	} else {
		tmp = (1.0 / cbrt(x)) * (pow(cbrt(x), -1.0) * 0.3333333333333333);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 5e+76)
		tmp = Float64(fma(cbrt((x ^ -2.0)), 0.06172839506172839, fma(cbrt((x ^ 4.0)), 0.3333333333333333, Float64(-0.1111111111111111 * cbrt(x)))) / Float64(x * x));
	else
		tmp = Float64(Float64(1.0 / cbrt(x)) * Float64((cbrt(x) ^ -1.0) * 0.3333333333333333));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 5e+76], N[(N[(N[Power[N[Power[x, -2.0], $MachinePrecision], 1/3], $MachinePrecision] * 0.06172839506172839 + N[(N[Power[N[Power[x, 4.0], $MachinePrecision], 1/3], $MachinePrecision] * 0.3333333333333333 + N[(-0.1111111111111111 * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision] * N[(N[Power[N[Power[x, 1/3], $MachinePrecision], -1.0], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 5 \cdot 10^{+76}:\\
\;\;\;\;\frac{\mathsf{fma}\left(\sqrt[3]{{x}^{-2}}, 0.06172839506172839, \mathsf{fma}\left(\sqrt[3]{{x}^{4}}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)\right)}{x \cdot x}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot 0.3333333333333333\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4.99999999999999991e76

    1. Initial program 13.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{\frac{-1}{9} \cdot \sqrt[3]{x} + \left(\frac{5}{81} \cdot \sqrt[3]{\frac{1}{{x}^{2}}} + \frac{1}{3} \cdot \sqrt[3]{{x}^{4}}\right)}{{x}^{2}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\frac{-1}{9} \cdot \sqrt[3]{x} + \left(\frac{5}{81} \cdot \sqrt[3]{\frac{1}{{x}^{2}}} + \frac{1}{3} \cdot \sqrt[3]{{x}^{4}}\right)}{\color{blue}{{x}^{2}}} \]
    5. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\sqrt[3]{{x}^{-2}}, 0.06172839506172839, \mathsf{fma}\left(\sqrt[3]{{x}^{4}}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)\right)}{x \cdot x}} \]

    if 4.99999999999999991e76 < x

    1. Initial program 4.4%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval36.5

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites36.5%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      10. pow2N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      11. lower-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      12. lift-cbrt.f6498.3

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    7. Applied rewrites98.3%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

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

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      3. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      5. associate-*l/N/A

        \[\leadsto \frac{1 \cdot \frac{1}{3}}{\color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}} \]
      6. unpow2N/A

        \[\leadsto \frac{1 \cdot \frac{1}{3}}{\sqrt[3]{x} \cdot \color{blue}{\sqrt[3]{x}}} \]
      7. times-fracN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{\frac{1}{3}}{\sqrt[3]{x}}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{\frac{1}{3}}{\sqrt[3]{x}}} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\color{blue}{\frac{1}{3}}}{\sqrt[3]{x}} \]
      10. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
      11. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
      12. lift-cbrt.f6498.3

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}} \]
    9. Applied rewrites98.3%

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{0.3333333333333333}{\sqrt[3]{x}}} \]
    10. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
      2. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{1 \cdot \frac{1}{3}}{\sqrt[3]{\color{blue}{x}}} \]
      3. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{1 \cdot \frac{1}{3}}{\sqrt[3]{x}} \]
      4. associate-*l/N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{3}}\right) \]
      5. lower-*.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{3}}\right) \]
      6. inv-powN/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right) \]
      7. lower-pow.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right) \]
      8. lift-cbrt.f6498.4

        \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot 0.3333333333333333\right) \]
    11. Applied rewrites98.4%

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \color{blue}{0.3333333333333333}\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 96.5% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (* (pow (cbrt x) -1.0) -0.3333333333333333) (- (cbrt x))))
double code(double x) {
	return (pow(cbrt(x), -1.0) * -0.3333333333333333) / -cbrt(x);
}
public static double code(double x) {
	return (Math.pow(Math.cbrt(x), -1.0) * -0.3333333333333333) / -Math.cbrt(x);
}
function code(x)
	return Float64(Float64((cbrt(x) ^ -1.0) * -0.3333333333333333) / Float64(-cbrt(x)))
end
code[x_] := N[(N[(N[Power[N[Power[x, 1/3], $MachinePrecision], -1.0], $MachinePrecision] * -0.3333333333333333), $MachinePrecision] / (-N[Power[x, 1/3], $MachinePrecision])), $MachinePrecision]
\begin{array}{l}

\\
\frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}}
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    2. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    3. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    5. lower-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    6. metadata-eval49.7

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
  5. Applied rewrites49.7%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    2. lift-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    3. metadata-evalN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    5. cbrt-divN/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    7. unpow2N/A

      \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
    8. cbrt-prodN/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    10. pow2N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    11. lower-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    12. lift-cbrt.f6496.7

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  7. Applied rewrites96.7%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  8. Step-by-step derivation
    1. pow1/396.7

      \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}} \cdot 0.3333333333333333 \]
    2. lift-/.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    3. lift-cbrt.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    4. lift-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    5. pow-flipN/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{\left(\mathsf{neg}\left(2\right)\right)} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    7. lower-pow.f64N/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    8. lift-cbrt.f6496.7

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333 \]
  9. Applied rewrites96.7%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333} \]
  10. Step-by-step derivation
    1. lift-*.f64N/A

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

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    3. lift-pow.f64N/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    4. metadata-evalN/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{\left(2 \cdot -1\right)} \cdot \frac{1}{3} \]
    5. pow-sqrN/A

      \[\leadsto \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3} \]
    6. inv-powN/A

      \[\leadsto \left(\frac{1}{\sqrt[3]{x}} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3} \]
    7. inv-powN/A

      \[\leadsto \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right) \cdot \frac{1}{3} \]
    8. associate-*l*N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{3}\right)} \]
    9. associate-*l/N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{1 \cdot \frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{\color{blue}{x}}} \]
    11. frac-2negN/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\color{blue}{\mathsf{neg}\left(\sqrt[3]{x}\right)}} \]
    12. pow1/3N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\mathsf{neg}\left({x}^{\frac{1}{3}}\right)} \]
    13. sqr-powN/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)} \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)} \]
    14. distribute-lft-neg-inN/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\mathsf{neg}\left(\frac{1}{3}\right)}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot \color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
    15. associate-*r/N/A

      \[\leadsto \frac{\frac{1}{\sqrt[3]{x}} \cdot \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)}{\color{blue}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
    16. lower-/.f64N/A

      \[\leadsto \frac{\frac{1}{\sqrt[3]{x}} \cdot \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)}{\color{blue}{\left(\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)\right) \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}} \]
  11. Applied rewrites96.7%

    \[\leadsto \frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{\color{blue}{-\sqrt[3]{x}}} \]
  12. Final simplification96.7%

    \[\leadsto \frac{{\left(\sqrt[3]{x}\right)}^{-1} \cdot -0.3333333333333333}{-\sqrt[3]{x}} \]
  13. Add Preprocessing

Alternative 4: 96.5% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \sqrt[3]{{x}^{-1}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* (cbrt (pow x -1.0)) (/ 0.3333333333333333 (cbrt x))))
double code(double x) {
	return cbrt(pow(x, -1.0)) * (0.3333333333333333 / cbrt(x));
}
public static double code(double x) {
	return Math.cbrt(Math.pow(x, -1.0)) * (0.3333333333333333 / Math.cbrt(x));
}
function code(x)
	return Float64(cbrt((x ^ -1.0)) * Float64(0.3333333333333333 / cbrt(x)))
end
code[x_] := N[(N[Power[N[Power[x, -1.0], $MachinePrecision], 1/3], $MachinePrecision] * N[(0.3333333333333333 / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{{x}^{-1}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}}
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    2. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    3. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    5. lower-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    6. metadata-eval49.7

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
  5. Applied rewrites49.7%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    2. lift-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    3. metadata-evalN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    5. cbrt-divN/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    7. unpow2N/A

      \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
    8. cbrt-prodN/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    10. pow2N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    11. lower-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    12. lift-cbrt.f6496.7

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  7. Applied rewrites96.7%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  8. Step-by-step derivation
    1. lift-*.f64N/A

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

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    3. lift-cbrt.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    4. lift-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    5. associate-*l/N/A

      \[\leadsto \frac{1 \cdot \frac{1}{3}}{\color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}} \]
    6. unpow2N/A

      \[\leadsto \frac{1 \cdot \frac{1}{3}}{\sqrt[3]{x} \cdot \color{blue}{\sqrt[3]{x}}} \]
    7. times-fracN/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{\frac{1}{3}}{\sqrt[3]{x}}} \]
    8. lower-*.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{\frac{1}{3}}{\sqrt[3]{x}}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\color{blue}{\frac{1}{3}}}{\sqrt[3]{x}} \]
    10. lift-cbrt.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
    11. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
    12. lift-cbrt.f6496.7

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}} \]
  9. Applied rewrites96.7%

    \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{0.3333333333333333}{\sqrt[3]{x}}} \]
  10. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x}} \cdot \frac{\color{blue}{\frac{1}{3}}}{\sqrt[3]{x}} \]
    2. metadata-evalN/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
    3. lift-cbrt.f64N/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
    4. cbrt-divN/A

      \[\leadsto \sqrt[3]{\frac{1}{x}} \cdot \frac{\color{blue}{\frac{1}{3}}}{\sqrt[3]{x}} \]
    5. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{x}} \cdot \frac{\color{blue}{\frac{1}{3}}}{\sqrt[3]{x}} \]
    6. inv-powN/A

      \[\leadsto \sqrt[3]{{x}^{-1}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
    7. lower-pow.f6496.7

      \[\leadsto \sqrt[3]{{x}^{-1}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}} \]
  11. Applied rewrites96.7%

    \[\leadsto \sqrt[3]{{x}^{-1}} \cdot \frac{\color{blue}{0.3333333333333333}}{\sqrt[3]{x}} \]
  12. Add Preprocessing

Alternative 5: 96.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333 \end{array} \]
(FPCore (x) :precision binary64 (* (pow (cbrt x) -2.0) 0.3333333333333333))
double code(double x) {
	return pow(cbrt(x), -2.0) * 0.3333333333333333;
}
public static double code(double x) {
	return Math.pow(Math.cbrt(x), -2.0) * 0.3333333333333333;
}
function code(x)
	return Float64((cbrt(x) ^ -2.0) * 0.3333333333333333)
end
code[x_] := N[(N[Power[N[Power[x, 1/3], $MachinePrecision], -2.0], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}

\\
{\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    2. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    3. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    5. lower-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    6. metadata-eval49.7

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
  5. Applied rewrites49.7%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    2. lift-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    3. metadata-evalN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    5. cbrt-divN/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    7. unpow2N/A

      \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
    8. cbrt-prodN/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    10. pow2N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    11. lower-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    12. lift-cbrt.f6496.7

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  7. Applied rewrites96.7%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  8. Step-by-step derivation
    1. pow1/396.7

      \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}} \cdot 0.3333333333333333 \]
    2. lift-/.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    3. lift-cbrt.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    4. lift-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    5. pow-flipN/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{\left(\mathsf{neg}\left(2\right)\right)} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    7. lower-pow.f64N/A

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot \frac{1}{3} \]
    8. lift-cbrt.f6496.7

      \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333 \]
  9. Applied rewrites96.7%

    \[\leadsto \color{blue}{{\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333} \]
  10. Final simplification96.7%

    \[\leadsto {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333 \]
  11. Add Preprocessing

Alternative 6: 92.1% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.35e+154)
   (* (/ 1.0 (cbrt (* x x))) 0.3333333333333333)
   (* (/ 1.0 (pow x 0.6666666666666666)) 0.3333333333333333)))
double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = (1.0 / cbrt((x * x))) * 0.3333333333333333;
	} else {
		tmp = (1.0 / pow(x, 0.6666666666666666)) * 0.3333333333333333;
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = (1.0 / Math.cbrt((x * x))) * 0.3333333333333333;
	} else {
		tmp = (1.0 / Math.pow(x, 0.6666666666666666)) * 0.3333333333333333;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.35e+154)
		tmp = Float64(Float64(1.0 / cbrt(Float64(x * x))) * 0.3333333333333333);
	else
		tmp = Float64(Float64(1.0 / (x ^ 0.6666666666666666)) * 0.3333333333333333);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.35e+154], N[(N[(1.0 / N[Power[N[(x * x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision], N[(N[(1.0 / N[Power[x, 0.6666666666666666], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\
\;\;\;\;\frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.35000000000000003e154

    1. Initial program 8.9%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval95.2

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites95.2%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      10. pow2N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      11. lower-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      12. lift-cbrt.f6494.8

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    7. Applied rewrites94.8%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      3. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      4. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      5. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. lower-cbrt.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. lower-*.f6495.5

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333 \]
    9. Applied rewrites95.5%

      \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333 \]

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval10.2

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites10.2%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      10. pow2N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      11. lower-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      12. lift-cbrt.f6498.3

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    7. Applied rewrites98.3%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      3. pow1/3N/A

        \[\leadsto \frac{1}{{\left({x}^{\frac{1}{3}}\right)}^{2}} \cdot \frac{1}{3} \]
      4. pow-powN/A

        \[\leadsto \frac{1}{{x}^{\left(\frac{1}{3} \cdot 2\right)}} \cdot \frac{1}{3} \]
      5. metadata-evalN/A

        \[\leadsto \frac{1}{{x}^{\frac{2}{3}}} \cdot \frac{1}{3} \]
      6. lower-pow.f6489.1

        \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    9. Applied rewrites89.1%

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 92.1% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.35e+154)
   (/ -0.3333333333333333 (cbrt (* (- x) x)))
   (* (/ 1.0 (pow x 0.6666666666666666)) 0.3333333333333333)))
double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = -0.3333333333333333 / cbrt((-x * x));
	} else {
		tmp = (1.0 / pow(x, 0.6666666666666666)) * 0.3333333333333333;
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = -0.3333333333333333 / Math.cbrt((-x * x));
	} else {
		tmp = (1.0 / Math.pow(x, 0.6666666666666666)) * 0.3333333333333333;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.35e+154)
		tmp = Float64(-0.3333333333333333 / cbrt(Float64(Float64(-x) * x)));
	else
		tmp = Float64(Float64(1.0 / (x ^ 0.6666666666666666)) * 0.3333333333333333);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.35e+154], N[(-0.3333333333333333 / N[Power[N[((-x) * x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[Power[x, 0.6666666666666666], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\
\;\;\;\;\frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.35000000000000003e154

    1. Initial program 8.9%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval95.2

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites95.2%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. frac-2negN/A

        \[\leadsto \sqrt[3]{\frac{\mathsf{neg}\left(1\right)}{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \sqrt[3]{\frac{-1}{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      7. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{-1}}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      8. metadata-evalN/A

        \[\leadsto \frac{\sqrt[3]{{-1}^{3}}}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      9. rem-cbrt-cubeN/A

        \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      11. lower-cbrt.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      12. unpow2N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left(x \cdot x\right)}} \cdot \frac{1}{3} \]
      13. distribute-lft-neg-inN/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
      14. lower-*.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
      15. lower-neg.f6495.5

        \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot 0.3333333333333333 \]
    7. Applied rewrites95.5%

      \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. pow1/395.5

        \[\leadsto \frac{-1}{\color{blue}{\sqrt[3]{\left(-x\right) \cdot x}}} \cdot 0.3333333333333333 \]
      2. lift-*.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot \frac{1}{3} \]
      4. lift-cbrt.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot \frac{1}{3} \]
      5. lift-neg.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
      7. associate-*l/N/A

        \[\leadsto \frac{-1 \cdot \frac{1}{3}}{\color{blue}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}}} \]
      8. metadata-evalN/A

        \[\leadsto \frac{\frac{-1}{3}}{\sqrt[3]{\color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot x}}} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{\frac{-1}{3}}{\color{blue}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}}} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{\frac{-1}{3}}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \]
      11. lift-neg.f64N/A

        \[\leadsto \frac{\frac{-1}{3}}{\sqrt[3]{\left(-x\right) \cdot x}} \]
      12. lift-cbrt.f6495.4

        \[\leadsto \frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}} \]
    9. Applied rewrites95.4%

      \[\leadsto \color{blue}{\frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}}} \]

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
      3. lower-cbrt.f64N/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      5. lower-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      6. metadata-eval10.2

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
    5. Applied rewrites10.2%

      \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
      3. metadata-evalN/A

        \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
      4. pow-flipN/A

        \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
      5. cbrt-divN/A

        \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      8. cbrt-prodN/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      9. lower-/.f64N/A

        \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
      10. pow2N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      11. lower-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      12. lift-cbrt.f6498.3

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    7. Applied rewrites98.3%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
    8. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
      3. pow1/3N/A

        \[\leadsto \frac{1}{{\left({x}^{\frac{1}{3}}\right)}^{2}} \cdot \frac{1}{3} \]
      4. pow-powN/A

        \[\leadsto \frac{1}{{x}^{\left(\frac{1}{3} \cdot 2\right)}} \cdot \frac{1}{3} \]
      5. metadata-evalN/A

        \[\leadsto \frac{1}{{x}^{\frac{2}{3}}} \cdot \frac{1}{3} \]
      6. lower-pow.f6489.1

        \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    9. Applied rewrites89.1%

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification92.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 88.8% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \end{array} \]
(FPCore (x)
 :precision binary64
 (* (/ 1.0 (pow x 0.6666666666666666)) 0.3333333333333333))
double code(double x) {
	return (1.0 / pow(x, 0.6666666666666666)) * 0.3333333333333333;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = (1.0d0 / (x ** 0.6666666666666666d0)) * 0.3333333333333333d0
end function
public static double code(double x) {
	return (1.0 / Math.pow(x, 0.6666666666666666)) * 0.3333333333333333;
}
def code(x):
	return (1.0 / math.pow(x, 0.6666666666666666)) * 0.3333333333333333
function code(x)
	return Float64(Float64(1.0 / (x ^ 0.6666666666666666)) * 0.3333333333333333)
end
function tmp = code(x)
	tmp = (1.0 / (x ^ 0.6666666666666666)) * 0.3333333333333333;
end
code[x_] := N[(N[(1.0 / N[Power[x, 0.6666666666666666], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    2. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    3. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    5. lower-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    6. metadata-eval49.7

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
  5. Applied rewrites49.7%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    2. lift-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    3. metadata-evalN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    5. cbrt-divN/A

      \[\leadsto \frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    7. unpow2N/A

      \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
    8. cbrt-prodN/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    10. pow2N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    11. lower-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    12. lift-cbrt.f6496.7

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  7. Applied rewrites96.7%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  8. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    3. pow1/3N/A

      \[\leadsto \frac{1}{{\left({x}^{\frac{1}{3}}\right)}^{2}} \cdot \frac{1}{3} \]
    4. pow-powN/A

      \[\leadsto \frac{1}{{x}^{\left(\frac{1}{3} \cdot 2\right)}} \cdot \frac{1}{3} \]
    5. metadata-evalN/A

      \[\leadsto \frac{1}{{x}^{\frac{2}{3}}} \cdot \frac{1}{3} \]
    6. lower-pow.f6489.0

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  9. Applied rewrites89.0%

    \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  10. Add Preprocessing

Alternative 9: 88.8% accurate, 1.9× speedup?

\[\begin{array}{l} \\ {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \end{array} \]
(FPCore (x)
 :precision binary64
 (* (pow x -0.6666666666666666) 0.3333333333333333))
double code(double x) {
	return pow(x, -0.6666666666666666) * 0.3333333333333333;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = (x ** (-0.6666666666666666d0)) * 0.3333333333333333d0
end function
public static double code(double x) {
	return Math.pow(x, -0.6666666666666666) * 0.3333333333333333;
}
def code(x):
	return math.pow(x, -0.6666666666666666) * 0.3333333333333333
function code(x)
	return Float64((x ^ -0.6666666666666666) * 0.3333333333333333)
end
function tmp = code(x)
	tmp = (x ^ -0.6666666666666666) * 0.3333333333333333;
end
code[x_] := N[(N[Power[x, -0.6666666666666666], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}

\\
{x}^{-0.6666666666666666} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    2. lower-*.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{\frac{1}{3}} \]
    3. lower-cbrt.f64N/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{2}}} \cdot \frac{1}{3} \]
    4. pow-flipN/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    5. lower-pow.f64N/A

      \[\leadsto \sqrt[3]{{x}^{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \frac{1}{3} \]
    6. metadata-eval49.7

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333 \]
  5. Applied rewrites49.7%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto \sqrt[3]{{x}^{-2}} \cdot \frac{1}{3} \]
    2. pow1/3N/A

      \[\leadsto {\left({x}^{-2}\right)}^{\frac{1}{3}} \cdot \frac{1}{3} \]
    3. lift-pow.f64N/A

      \[\leadsto {\left({x}^{-2}\right)}^{\frac{1}{3}} \cdot \frac{1}{3} \]
    4. pow-powN/A

      \[\leadsto {x}^{\left(-2 \cdot \frac{1}{3}\right)} \cdot \frac{1}{3} \]
    5. metadata-evalN/A

      \[\leadsto {x}^{\frac{-2}{3}} \cdot \frac{1}{3} \]
    6. metadata-evalN/A

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    7. lower-pow.f64N/A

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    8. metadata-eval89.0

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  7. Applied rewrites89.0%

    \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  8. Add Preprocessing

Alternative 10: 1.8% accurate, 2.0× speedup?

\[\begin{array}{l} \\ 1 - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- 1.0 (cbrt x)))
double code(double x) {
	return 1.0 - cbrt(x);
}
public static double code(double x) {
	return 1.0 - Math.cbrt(x);
}
function code(x)
	return Float64(1.0 - cbrt(x))
end
code[x_] := N[(1.0 - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 - \sqrt[3]{x}
\end{array}
Derivation
  1. Initial program 6.7%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{1} - \sqrt[3]{x} \]
  4. Step-by-step derivation
    1. Applied rewrites1.8%

      \[\leadsto \color{blue}{1} - \sqrt[3]{x} \]
    2. Add Preprocessing

    Developer Target 1: 98.5% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{x + 1}\\ \frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}} \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (cbrt (+ x 1.0))))
       (/ 1.0 (+ (+ (* t_0 t_0) (* (cbrt x) t_0)) (* (cbrt x) (cbrt x))))))
    double code(double x) {
    	double t_0 = cbrt((x + 1.0));
    	return 1.0 / (((t_0 * t_0) + (cbrt(x) * t_0)) + (cbrt(x) * cbrt(x)));
    }
    
    public static double code(double x) {
    	double t_0 = Math.cbrt((x + 1.0));
    	return 1.0 / (((t_0 * t_0) + (Math.cbrt(x) * t_0)) + (Math.cbrt(x) * Math.cbrt(x)));
    }
    
    function code(x)
    	t_0 = cbrt(Float64(x + 1.0))
    	return Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) + Float64(cbrt(x) * t_0)) + Float64(cbrt(x) * cbrt(x))))
    end
    
    code[x_] := Block[{t$95$0 = N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]}, N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \sqrt[3]{x + 1}\\
    \frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}}
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2025073 
    (FPCore (x)
      :name "2cbrt (problem 3.3.4)"
      :precision binary64
      :pre (and (> x 1.0) (< x 1e+308))
    
      :alt
      (! :herbie-platform default (/ 1 (+ (* (cbrt (+ x 1)) (cbrt (+ x 1))) (* (cbrt x) (cbrt (+ x 1))) (* (cbrt x) (cbrt x)))))
    
      (- (cbrt (+ x 1.0)) (cbrt x)))