2cbrt (problem 3.3.4)

Percentage Accurate: 6.7% → 98.9%
Time: 11.0s
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: 6.7% 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: 98.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 4.5 \cdot 10^{+14}:\\ \;\;\;\;\frac{\left(x + 1\right) - x}{{\left(x + 1\right)}^{0.6666666666666666} + \left({x}^{0.6666666666666666} + \sqrt[3]{\mathsf{fma}\left(x, x, x\right)}\right)}\\ \mathbf{else}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 4.5e+14)
   (/
    (- (+ x 1.0) x)
    (+
     (pow (+ x 1.0) 0.6666666666666666)
     (+ (pow x 0.6666666666666666) (cbrt (fma x x x)))))
   (* 0.3333333333333333 (/ 1.0 (/ x (cbrt x))))))
double code(double x) {
	double tmp;
	if (x <= 4.5e+14) {
		tmp = ((x + 1.0) - x) / (pow((x + 1.0), 0.6666666666666666) + (pow(x, 0.6666666666666666) + cbrt(fma(x, x, x))));
	} else {
		tmp = 0.3333333333333333 * (1.0 / (x / cbrt(x)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 4.5e+14)
		tmp = Float64(Float64(Float64(x + 1.0) - x) / Float64((Float64(x + 1.0) ^ 0.6666666666666666) + Float64((x ^ 0.6666666666666666) + cbrt(fma(x, x, x)))));
	else
		tmp = Float64(0.3333333333333333 * Float64(1.0 / Float64(x / cbrt(x))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 4.5e+14], N[(N[(N[(x + 1.0), $MachinePrecision] - x), $MachinePrecision] / N[(N[Power[N[(x + 1.0), $MachinePrecision], 0.6666666666666666], $MachinePrecision] + N[(N[Power[x, 0.6666666666666666], $MachinePrecision] + N[Power[N[(x * x + x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.3333333333333333 * N[(1.0 / N[(x / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 4.5 \cdot 10^{+14}:\\
\;\;\;\;\frac{\left(x + 1\right) - x}{{\left(x + 1\right)}^{0.6666666666666666} + \left({x}^{0.6666666666666666} + \sqrt[3]{\mathsf{fma}\left(x, x, x\right)}\right)}\\

\mathbf{else}:\\
\;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4.5e14

    1. Initial program 62.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing
    3. Applied rewrites97.5%

      \[\leadsto \color{blue}{\frac{\left(-\left(x + 1\right)\right) + x}{-\left({\left(x + 1\right)}^{0.6666666666666666} + \left({x}^{0.6666666666666666} + \sqrt[3]{\mathsf{fma}\left(x, x, x\right)}\right)\right)}} \]

    if 4.5e14 < 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. lower-*.f64N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
      5. associate-*r/N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
      9. lower-*.f6445.7

        \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    5. Applied rewrites45.7%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x \cdot x}}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}}}\right) \]
      16. lower-/.f6498.4

        \[\leadsto 0.3333333333333333 \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{\sqrt[3]{x}}}\right) \]
    7. Applied rewrites98.4%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right)} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{x}\right)}^{\frac{1}{3}} \cdot \color{blue}{{\left(\frac{1}{x}\right)}^{\frac{1}{3}}}\right) \]
      9. unpow-prod-downN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{{\left(\frac{1}{x} \cdot \frac{1}{x}\right)}^{\frac{1}{3}}} \]
      10. pow2N/A

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

        \[\leadsto \frac{1}{3} \cdot {\left({\color{blue}{\left(\frac{1}{x}\right)}}^{2}\right)}^{\frac{1}{3}} \]
      12. inv-powN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot {x}^{\left(\color{blue}{\left(\mathsf{neg}\left(5\right)\right)} \cdot \frac{1}{3} + 1\right)} \]
      20. pow-plusN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)} \cdot x\right)} \]
      21. pow-powN/A

        \[\leadsto \frac{1}{3} \cdot \left(\color{blue}{{\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}} \cdot x\right) \]
      22. pow-flipN/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      23. lift-pow.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{\color{blue}{{x}^{5}}}\right)}^{\frac{1}{3}} \cdot x\right) \]
      24. lift-/.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      25. pow1/3N/A

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left(x \cdot \sqrt[3]{\frac{1}{{x}^{5}}}\right)} \]
    9. Applied rewrites50.3%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{1}{\frac{{x}^{1.6666666666666667}}{x}}} \]
    10. Applied rewrites99.1%

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{\color{blue}{\frac{x}{\sqrt[3]{x} + 0}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 4.5 \cdot 10^{+14}:\\ \;\;\;\;\frac{\left(x + 1\right) - x}{{\left(x + 1\right)}^{0.6666666666666666} + \left({x}^{0.6666666666666666} + \sqrt[3]{\mathsf{fma}\left(x, x, x\right)}\right)}\\ \mathbf{else}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\sqrt[3]{x + 1} - \sqrt[3]{x} \leq 2 \cdot 10^{-7}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \mathbf{else}:\\ \;\;\;\;{\left(x + -1\right)}^{-0.3333333333333333} \cdot \sqrt[3]{\mathsf{fma}\left(x, x, -1\right)} - \sqrt[3]{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (- (cbrt (+ x 1.0)) (cbrt x)) 2e-7)
   (* 0.3333333333333333 (/ 1.0 (/ x (cbrt x))))
   (-
    (* (pow (+ x -1.0) -0.3333333333333333) (cbrt (fma x x -1.0)))
    (cbrt x))))
double code(double x) {
	double tmp;
	if ((cbrt((x + 1.0)) - cbrt(x)) <= 2e-7) {
		tmp = 0.3333333333333333 * (1.0 / (x / cbrt(x)));
	} else {
		tmp = (pow((x + -1.0), -0.3333333333333333) * cbrt(fma(x, x, -1.0))) - cbrt(x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (Float64(cbrt(Float64(x + 1.0)) - cbrt(x)) <= 2e-7)
		tmp = Float64(0.3333333333333333 * Float64(1.0 / Float64(x / cbrt(x))));
	else
		tmp = Float64(Float64((Float64(x + -1.0) ^ -0.3333333333333333) * cbrt(fma(x, x, -1.0))) - cbrt(x));
	end
	return tmp
end
code[x_] := If[LessEqual[N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision], 2e-7], N[(0.3333333333333333 * N[(1.0 / N[(x / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Power[N[(x + -1.0), $MachinePrecision], -0.3333333333333333], $MachinePrecision] * N[Power[N[(x * x + -1.0), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\sqrt[3]{x + 1} - \sqrt[3]{x} \leq 2 \cdot 10^{-7}:\\
\;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (cbrt.f64 (+.f64 x #s(literal 1 binary64))) (cbrt.f64 x)) < 1.9999999999999999e-7

    1. Initial program 5.6%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    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. lower-*.f64N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
      5. associate-*r/N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
      9. lower-*.f6446.8

        \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    5. Applied rewrites46.8%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x \cdot x}}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}}}\right) \]
      16. lower-/.f6497.8

        \[\leadsto 0.3333333333333333 \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{\sqrt[3]{x}}}\right) \]
    7. Applied rewrites97.8%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right)} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{x}\right)}^{\frac{1}{3}} \cdot \color{blue}{{\left(\frac{1}{x}\right)}^{\frac{1}{3}}}\right) \]
      9. unpow-prod-downN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{{\left(\frac{1}{x} \cdot \frac{1}{x}\right)}^{\frac{1}{3}}} \]
      10. pow2N/A

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

        \[\leadsto \frac{1}{3} \cdot {\left({\color{blue}{\left(\frac{1}{x}\right)}}^{2}\right)}^{\frac{1}{3}} \]
      12. inv-powN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot {x}^{\left(\color{blue}{\left(\mathsf{neg}\left(5\right)\right)} \cdot \frac{1}{3} + 1\right)} \]
      20. pow-plusN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)} \cdot x\right)} \]
      21. pow-powN/A

        \[\leadsto \frac{1}{3} \cdot \left(\color{blue}{{\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}} \cdot x\right) \]
      22. pow-flipN/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      23. lift-pow.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{\color{blue}{{x}^{5}}}\right)}^{\frac{1}{3}} \cdot x\right) \]
      24. lift-/.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      25. pow1/3N/A

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left(x \cdot \sqrt[3]{\frac{1}{{x}^{5}}}\right)} \]
    9. Applied rewrites51.2%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{1}{\frac{{x}^{1.6666666666666667}}{x}}} \]
    10. Applied rewrites98.4%

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{\color{blue}{\frac{x}{\sqrt[3]{x} + 0}}} \]

    if 1.9999999999999999e-7 < (-.f64 (cbrt.f64 (+.f64 x #s(literal 1 binary64))) (cbrt.f64 x))

    1. Initial program 87.1%

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

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

        \[\leadsto \sqrt[3]{\color{blue}{\frac{1}{\frac{x - 1}{x \cdot x - 1 \cdot 1}}}} - \sqrt[3]{x} \]
      3. associate-/r/N/A

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

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

        \[\leadsto \color{blue}{\sqrt[3]{\frac{1}{x - 1}} \cdot \sqrt[3]{x \cdot x - 1 \cdot 1}} - \sqrt[3]{x} \]
      6. pow1/3N/A

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

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

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

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

        \[\leadsto \color{blue}{{\left(x - 1\right)}^{\left(\left(\mathsf{neg}\left(1\right)\right) \cdot \frac{1}{3}\right)}} \cdot \sqrt[3]{x \cdot x - 1 \cdot 1} - \sqrt[3]{x} \]
      11. sub-negN/A

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

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

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

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

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

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

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

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

        \[\leadsto {\left(x + -1\right)}^{\frac{-1}{3}} \cdot \sqrt[3]{\color{blue}{\mathsf{fma}\left(x, x, \mathsf{neg}\left(1\right)\right)}} - \sqrt[3]{x} \]
      20. metadata-eval89.5

        \[\leadsto {\left(x + -1\right)}^{-0.3333333333333333} \cdot \sqrt[3]{\mathsf{fma}\left(x, x, \color{blue}{-1}\right)} - \sqrt[3]{x} \]
    4. Applied rewrites89.5%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;\sqrt[3]{x + 1} - \sqrt[3]{x} \leq 2 \cdot 10^{-7}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \mathbf{else}:\\ \;\;\;\;{\left(x + -1\right)}^{-0.3333333333333333} \cdot \sqrt[3]{\mathsf{fma}\left(x, x, -1\right)} - \sqrt[3]{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.1% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 33000000:\\ \;\;\;\;\mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \frac{1}{{\left(x + 1\right)}^{-0.3333333333333333}}\right)\\ \mathbf{else}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 33000000.0)
   (fma
    (pow x 0.16666666666666666)
    (- (pow x 0.16666666666666666))
    (/ 1.0 (pow (+ x 1.0) -0.3333333333333333)))
   (* 0.3333333333333333 (/ 1.0 (/ x (cbrt x))))))
double code(double x) {
	double tmp;
	if (x <= 33000000.0) {
		tmp = fma(pow(x, 0.16666666666666666), -pow(x, 0.16666666666666666), (1.0 / pow((x + 1.0), -0.3333333333333333)));
	} else {
		tmp = 0.3333333333333333 * (1.0 / (x / cbrt(x)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 33000000.0)
		tmp = fma((x ^ 0.16666666666666666), Float64(-(x ^ 0.16666666666666666)), Float64(1.0 / (Float64(x + 1.0) ^ -0.3333333333333333)));
	else
		tmp = Float64(0.3333333333333333 * Float64(1.0 / Float64(x / cbrt(x))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 33000000.0], N[(N[Power[x, 0.16666666666666666], $MachinePrecision] * (-N[Power[x, 0.16666666666666666], $MachinePrecision]) + N[(1.0 / N[Power[N[(x + 1.0), $MachinePrecision], -0.3333333333333333], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.3333333333333333 * N[(1.0 / N[(x / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 33000000:\\
\;\;\;\;\mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \frac{1}{{\left(x + 1\right)}^{-0.3333333333333333}}\right)\\

\mathbf{else}:\\
\;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.3e7

    1. Initial program 87.1%

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

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

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

        \[\leadsto \sqrt[3]{x + 1} - \color{blue}{\sqrt[3]{x}} \]
      4. sub-negN/A

        \[\leadsto \color{blue}{\sqrt[3]{x + 1} + \left(\mathsf{neg}\left(\sqrt[3]{x}\right)\right)} \]
      5. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\sqrt[3]{x}\right)\right) + \sqrt[3]{x + 1}} \]
      6. lift-cbrt.f64N/A

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

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

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)} \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}\right)\right) + \sqrt[3]{x + 1} \]
      9. distribute-rgt-neg-inN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right)} \]
      11. lower-pow.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right) \]
      12. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{\frac{1}{6}}}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right) \]
      13. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \color{blue}{\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)}, \sqrt[3]{x + 1}\right) \]
      14. lower-pow.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}\right), \sqrt[3]{x + 1}\right) \]
      15. metadata-eval87.3

        \[\leadsto \mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{\color{blue}{0.16666666666666666}}, \sqrt[3]{x + 1}\right) \]
    4. Applied rewrites87.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \sqrt[3]{x + 1}\right)} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \sqrt[3]{\color{blue}{x + 1}}\right) \]
      2. remove-double-divN/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \sqrt[3]{\color{blue}{\frac{1}{\frac{1}{x + 1}}}}\right) \]
      3. lift-/.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \sqrt[3]{\frac{1}{\color{blue}{\frac{1}{x + 1}}}}\right) \]
      4. cbrt-divN/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \color{blue}{\frac{\sqrt[3]{1}}{\sqrt[3]{\frac{1}{x + 1}}}}\right) \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{\color{blue}{1}}{\sqrt[3]{\frac{1}{x + 1}}}\right) \]
      6. lift-cbrt.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{\color{blue}{\sqrt[3]{\frac{1}{x + 1}}}}\right) \]
      7. lift-/.f6486.2

        \[\leadsto \mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \color{blue}{\frac{1}{\sqrt[3]{\frac{1}{x + 1}}}}\right) \]
      8. lift-cbrt.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{\color{blue}{\sqrt[3]{\frac{1}{x + 1}}}}\right) \]
      9. pow1/3N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{\color{blue}{{\left(\frac{1}{x + 1}\right)}^{\frac{1}{3}}}}\right) \]
      10. lift-/.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{{\color{blue}{\left(\frac{1}{x + 1}\right)}}^{\frac{1}{3}}}\right) \]
      11. inv-powN/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{{\color{blue}{\left({\left(x + 1\right)}^{-1}\right)}}^{\frac{1}{3}}}\right) \]
      12. pow-powN/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{\color{blue}{{\left(x + 1\right)}^{\left(-1 \cdot \frac{1}{3}\right)}}}\right) \]
      13. lower-pow.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{\color{blue}{{\left(x + 1\right)}^{\left(-1 \cdot \frac{1}{3}\right)}}}\right) \]
      14. lift-+.f64N/A

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{{\color{blue}{\left(x + 1\right)}}^{\left(-1 \cdot \frac{1}{3}\right)}}\right) \]
      15. +-commutativeN/A

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

        \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left({x}^{\frac{1}{6}}\right), \frac{1}{{\color{blue}{\left(1 + x\right)}}^{\left(-1 \cdot \frac{1}{3}\right)}}\right) \]
      17. metadata-eval90.4

        \[\leadsto \mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \frac{1}{{\left(1 + x\right)}^{\color{blue}{-0.3333333333333333}}}\right) \]
    6. Applied rewrites90.4%

      \[\leadsto \mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \color{blue}{\frac{1}{{\left(1 + x\right)}^{-0.3333333333333333}}}\right) \]

    if 3.3e7 < x

    1. Initial program 5.6%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    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. lower-*.f64N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
      5. associate-*r/N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
      9. lower-*.f6446.8

        \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    5. Applied rewrites46.8%

      \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x \cdot x}}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}}}\right) \]
      16. lower-/.f6497.8

        \[\leadsto 0.3333333333333333 \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{\sqrt[3]{x}}}\right) \]
    7. Applied rewrites97.8%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right)} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{x}\right)}^{\frac{1}{3}} \cdot \color{blue}{{\left(\frac{1}{x}\right)}^{\frac{1}{3}}}\right) \]
      9. unpow-prod-downN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{{\left(\frac{1}{x} \cdot \frac{1}{x}\right)}^{\frac{1}{3}}} \]
      10. pow2N/A

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

        \[\leadsto \frac{1}{3} \cdot {\left({\color{blue}{\left(\frac{1}{x}\right)}}^{2}\right)}^{\frac{1}{3}} \]
      12. inv-powN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot {x}^{\left(\color{blue}{\left(\mathsf{neg}\left(5\right)\right)} \cdot \frac{1}{3} + 1\right)} \]
      20. pow-plusN/A

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)} \cdot x\right)} \]
      21. pow-powN/A

        \[\leadsto \frac{1}{3} \cdot \left(\color{blue}{{\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}} \cdot x\right) \]
      22. pow-flipN/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      23. lift-pow.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{\color{blue}{{x}^{5}}}\right)}^{\frac{1}{3}} \cdot x\right) \]
      24. lift-/.f64N/A

        \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
      25. pow1/3N/A

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\left(x \cdot \sqrt[3]{\frac{1}{{x}^{5}}}\right)} \]
    9. Applied rewrites51.2%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{1}{\frac{{x}^{1.6666666666666667}}{x}}} \]
    10. Applied rewrites98.4%

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{\color{blue}{\frac{x}{\sqrt[3]{x} + 0}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 33000000:\\ \;\;\;\;\mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \frac{1}{{\left(x + 1\right)}^{-0.3333333333333333}}\right)\\ \mathbf{else}:\\ \;\;\;\;0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 92.2% accurate, 1.6× speedup?

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

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

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


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

    1. Initial program 11.3%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    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. lower-*.f64N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
      5. associate-*r/N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
      9. lower-*.f6493.6

        \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    5. Applied rewrites93.6%

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

    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. lower-*.f64N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
      5. associate-*r/N/A

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

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

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

        \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
      9. lower-*.f644.7

        \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    5. Applied rewrites4.7%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{3} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}} \cdot \sqrt[3]{x}} \]
      10. pow1/3N/A

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

        \[\leadsto \frac{1}{3} \cdot \frac{1}{{x}^{\frac{1}{3}} \cdot \color{blue}{\sqrt[3]{x}}} \]
      12. pow1/3N/A

        \[\leadsto \frac{1}{3} \cdot \frac{1}{{x}^{\frac{1}{3}} \cdot \color{blue}{{x}^{\frac{1}{3}}}} \]
      13. pow-prod-upN/A

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

        \[\leadsto \frac{1}{3} \cdot \frac{1}{\color{blue}{{x}^{\left(\frac{1}{3} + \frac{1}{3}\right)}}} \]
      15. metadata-eval89.1

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

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

Alternative 5: 97.3% accurate, 1.6× speedup?

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

\\
0.3333333333333333 \cdot \frac{1}{\frac{x}{\sqrt[3]{x}}}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  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. lower-*.f64N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
    5. associate-*r/N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    9. lower-*.f6446.4

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
  5. Applied rewrites46.4%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x \cdot x}}} \]
  6. Step-by-step derivation
    1. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{3} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}}}\right) \]
    16. lower-/.f6496.0

      \[\leadsto 0.3333333333333333 \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \color{blue}{\frac{1}{\sqrt[3]{x}}}\right) \]
  7. Applied rewrites96.0%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{\left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{\sqrt[3]{x}}\right)} \]
  8. Step-by-step derivation
    1. metadata-evalN/A

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{x}\right)}^{\frac{1}{3}} \cdot \color{blue}{{\left(\frac{1}{x}\right)}^{\frac{1}{3}}}\right) \]
    9. unpow-prod-downN/A

      \[\leadsto \frac{1}{3} \cdot \color{blue}{{\left(\frac{1}{x} \cdot \frac{1}{x}\right)}^{\frac{1}{3}}} \]
    10. pow2N/A

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

      \[\leadsto \frac{1}{3} \cdot {\left({\color{blue}{\left(\frac{1}{x}\right)}}^{2}\right)}^{\frac{1}{3}} \]
    12. inv-powN/A

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{3} \cdot {x}^{\left(\color{blue}{\left(\mathsf{neg}\left(5\right)\right)} \cdot \frac{1}{3} + 1\right)} \]
    20. pow-plusN/A

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)} \cdot x\right)} \]
    21. pow-powN/A

      \[\leadsto \frac{1}{3} \cdot \left(\color{blue}{{\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}} \cdot x\right) \]
    22. pow-flipN/A

      \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
    23. lift-pow.f64N/A

      \[\leadsto \frac{1}{3} \cdot \left({\left(\frac{1}{\color{blue}{{x}^{5}}}\right)}^{\frac{1}{3}} \cdot x\right) \]
    24. lift-/.f64N/A

      \[\leadsto \frac{1}{3} \cdot \left({\color{blue}{\left(\frac{1}{{x}^{5}}\right)}}^{\frac{1}{3}} \cdot x\right) \]
    25. pow1/3N/A

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\left(x \cdot \sqrt[3]{\frac{1}{{x}^{5}}}\right)} \]
  9. Applied rewrites50.7%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{1}{\frac{{x}^{1.6666666666666667}}{x}}} \]
  10. Applied rewrites96.6%

    \[\leadsto 0.3333333333333333 \cdot \frac{1}{\color{blue}{\frac{x}{\sqrt[3]{x} + 0}}} \]
  11. Final simplification96.6%

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

Alternative 6: 89.0% accurate, 1.8× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot \frac{1}{{x}^{0.6666666666666666}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (/ 1.0 (pow x 0.6666666666666666))))
double code(double x) {
	return 0.3333333333333333 * (1.0 / pow(x, 0.6666666666666666));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.3333333333333333d0 * (1.0d0 / (x ** 0.6666666666666666d0))
end function
public static double code(double x) {
	return 0.3333333333333333 * (1.0 / Math.pow(x, 0.6666666666666666));
}
def code(x):
	return 0.3333333333333333 * (1.0 / math.pow(x, 0.6666666666666666))
function code(x)
	return Float64(0.3333333333333333 * Float64(1.0 / (x ^ 0.6666666666666666)))
end
function tmp = code(x)
	tmp = 0.3333333333333333 * (1.0 / (x ^ 0.6666666666666666));
end
code[x_] := N[(0.3333333333333333 * N[(1.0 / N[Power[x, 0.6666666666666666], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot \frac{1}{{x}^{0.6666666666666666}}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  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. lower-*.f64N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
    5. associate-*r/N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    9. lower-*.f6446.4

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
  5. Applied rewrites46.4%

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{3} \cdot \frac{1}{\color{blue}{\sqrt[3]{x}} \cdot \sqrt[3]{x}} \]
    10. pow1/3N/A

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

      \[\leadsto \frac{1}{3} \cdot \frac{1}{{x}^{\frac{1}{3}} \cdot \color{blue}{\sqrt[3]{x}}} \]
    12. pow1/3N/A

      \[\leadsto \frac{1}{3} \cdot \frac{1}{{x}^{\frac{1}{3}} \cdot \color{blue}{{x}^{\frac{1}{3}}}} \]
    13. pow-prod-upN/A

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

      \[\leadsto \frac{1}{3} \cdot \frac{1}{\color{blue}{{x}^{\left(\frac{1}{3} + \frac{1}{3}\right)}}} \]
    15. metadata-eval88.2

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{{x}^{\color{blue}{0.6666666666666666}}} \]
  7. Applied rewrites88.2%

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

Alternative 7: 89.0% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \frac{0.3333333333333333}{{x}^{0.6666666666666666}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ 0.3333333333333333 (pow x 0.6666666666666666)))
double code(double x) {
	return 0.3333333333333333 / pow(x, 0.6666666666666666);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.3333333333333333d0 / (x ** 0.6666666666666666d0)
end function
public static double code(double x) {
	return 0.3333333333333333 / Math.pow(x, 0.6666666666666666);
}
def code(x):
	return 0.3333333333333333 / math.pow(x, 0.6666666666666666)
function code(x)
	return Float64(0.3333333333333333 / (x ^ 0.6666666666666666))
end
function tmp = code(x)
	tmp = 0.3333333333333333 / (x ^ 0.6666666666666666);
end
code[x_] := N[(0.3333333333333333 / N[Power[x, 0.6666666666666666], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.3333333333333333}{{x}^{0.6666666666666666}}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  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. lower-*.f64N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
    5. associate-*r/N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    9. lower-*.f6446.4

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
  5. Applied rewrites46.4%

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{3} \cdot \frac{1}{\sqrt[3]{x} \cdot \color{blue}{\sqrt[3]{x}}} \]
    8. un-div-invN/A

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

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

      \[\leadsto \frac{\frac{1}{3}}{\color{blue}{\sqrt[3]{x}} \cdot \sqrt[3]{x}} \]
    11. pow1/3N/A

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

      \[\leadsto \frac{\frac{1}{3}}{{x}^{\frac{1}{3}} \cdot \color{blue}{\sqrt[3]{x}}} \]
    13. pow1/3N/A

      \[\leadsto \frac{\frac{1}{3}}{{x}^{\frac{1}{3}} \cdot \color{blue}{{x}^{\frac{1}{3}}}} \]
    14. pow-prod-upN/A

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

      \[\leadsto \frac{\frac{1}{3}}{\color{blue}{{x}^{\left(\frac{1}{3} + \frac{1}{3}\right)}}} \]
    16. metadata-eval88.2

      \[\leadsto \frac{0.3333333333333333}{{x}^{\color{blue}{0.6666666666666666}}} \]
  7. Applied rewrites88.2%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{{x}^{0.6666666666666666}}} \]
  8. Add Preprocessing

Alternative 8: 89.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot {x}^{-0.6666666666666666} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (pow x -0.6666666666666666)))
double code(double x) {
	return 0.3333333333333333 * pow(x, -0.6666666666666666);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.3333333333333333d0 * (x ** (-0.6666666666666666d0))
end function
public static double code(double x) {
	return 0.3333333333333333 * Math.pow(x, -0.6666666666666666);
}
def code(x):
	return 0.3333333333333333 * math.pow(x, -0.6666666666666666)
function code(x)
	return Float64(0.3333333333333333 * (x ^ -0.6666666666666666))
end
function tmp = code(x)
	tmp = 0.3333333333333333 * (x ^ -0.6666666666666666);
end
code[x_] := N[(0.3333333333333333 * N[Power[x, -0.6666666666666666], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot {x}^{-0.6666666666666666}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  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. lower-*.f64N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}} \]
    5. associate-*r/N/A

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

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

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

      \[\leadsto \frac{1}{3} \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
    9. lower-*.f6446.4

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x \cdot x}}} \]
  5. Applied rewrites46.4%

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

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

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

      \[\leadsto \frac{1}{3} \cdot \color{blue}{\sqrt[3]{\frac{1}{x \cdot x}}} \]
    4. *-commutativeN/A

      \[\leadsto \color{blue}{\sqrt[3]{\frac{1}{x \cdot x}} \cdot \frac{1}{3}} \]
    5. lower-*.f6446.4

      \[\leadsto \color{blue}{\sqrt[3]{\frac{1}{x \cdot x}} \cdot 0.3333333333333333} \]
    6. lift-cbrt.f64N/A

      \[\leadsto \color{blue}{\sqrt[3]{\frac{1}{x \cdot x}}} \cdot \frac{1}{3} \]
    7. pow1/3N/A

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

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

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

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

      \[\leadsto {\color{blue}{\left(x \cdot x\right)}}^{\left(-1 \cdot \frac{1}{3}\right)} \cdot \frac{1}{3} \]
    12. pow2N/A

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot \color{blue}{-2}\right)} \cdot \frac{1}{3} \]
    20. metadata-eval88.2

      \[\leadsto {x}^{\color{blue}{-0.6666666666666666}} \cdot 0.3333333333333333 \]
  7. Applied rewrites88.2%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  8. Final simplification88.2%

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

Alternative 9: 5.3% accurate, 2.0× speedup?

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

\\
\sqrt[3]{x}
\end{array}
Derivation
  1. Initial program 7.8%

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

    \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
  4. Step-by-step derivation
    1. lower--.f64N/A

      \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
    2. lower-cbrt.f641.8

      \[\leadsto 1 - \color{blue}{\sqrt[3]{x}} \]
  5. Applied rewrites1.8%

    \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
  6. Applied rewrites5.3%

    \[\leadsto \color{blue}{\sqrt[3]{x} + 1} \]
  7. Taylor expanded in x around inf

    \[\leadsto \color{blue}{\sqrt[3]{x}} \]
  8. Step-by-step derivation
    1. lower-cbrt.f645.3

      \[\leadsto \color{blue}{\sqrt[3]{x}} \]
  9. Applied rewrites5.3%

    \[\leadsto \color{blue}{\sqrt[3]{x}} \]
  10. Add Preprocessing

Alternative 10: 4.1% accurate, 207.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (x) :precision binary64 0.0)
double code(double x) {
	return 0.0;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.0d0
end function
public static double code(double x) {
	return 0.0;
}
def code(x):
	return 0.0
function code(x)
	return 0.0
end
function tmp = code(x)
	tmp = 0.0;
end
code[x_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 7.8%

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

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

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

      \[\leadsto \sqrt[3]{x + 1} - \color{blue}{\sqrt[3]{x}} \]
    4. sub-negN/A

      \[\leadsto \color{blue}{\sqrt[3]{x + 1} + \left(\mathsf{neg}\left(\sqrt[3]{x}\right)\right)} \]
    5. +-commutativeN/A

      \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\sqrt[3]{x}\right)\right) + \sqrt[3]{x + 1}} \]
    6. lift-cbrt.f64N/A

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

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

      \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)} \cdot {x}^{\left(\frac{\frac{1}{3}}{2}\right)}}\right)\right) + \sqrt[3]{x + 1} \]
    9. distribute-rgt-neg-inN/A

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

      \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right)} \]
    11. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\color{blue}{\frac{1}{6}}}, \mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right), \sqrt[3]{x + 1}\right) \]
    13. lower-neg.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \color{blue}{\mathsf{neg}\left({x}^{\left(\frac{\frac{1}{3}}{2}\right)}\right)}, \sqrt[3]{x + 1}\right) \]
    14. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{1}{6}}, \mathsf{neg}\left(\color{blue}{{x}^{\left(\frac{\frac{1}{3}}{2}\right)}}\right), \sqrt[3]{x + 1}\right) \]
    15. metadata-eval8.6

      \[\leadsto \mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{\color{blue}{0.16666666666666666}}, \sqrt[3]{x + 1}\right) \]
  4. Applied rewrites8.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{0.16666666666666666}, -{x}^{0.16666666666666666}, \sqrt[3]{x + 1}\right)} \]
  5. Taylor expanded in x around inf

    \[\leadsto \color{blue}{x \cdot \left(\sqrt[3]{\frac{1}{{x}^{2}}} + -1 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right)} \]
  6. Step-by-step derivation
    1. distribute-rgt1-inN/A

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

      \[\leadsto x \cdot \left(\color{blue}{0} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    3. mul0-lftN/A

      \[\leadsto x \cdot \color{blue}{0} \]
    4. mul0-rgt4.2

      \[\leadsto \color{blue}{0} \]
  7. Applied rewrites4.2%

    \[\leadsto \color{blue}{0} \]
  8. 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 2024220 
(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)))