2cbrt (problem 3.3.4)

Percentage Accurate: 6.9% → 98.1%
Time: 10.5s
Alternatives: 10
Speedup: 2.0×

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: 6.9% 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: 98.1% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 48000000:\\ \;\;\;\;\sqrt[3]{\left(1 - x \cdot x\right) \cdot \frac{1}{1 - x}} - \sqrt[3]{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.3333333333333333}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 48000000.0)
   (- (cbrt (* (- 1.0 (* x x)) (/ 1.0 (- 1.0 x)))) (cbrt x))
   (/ 0.3333333333333333 (/ x (cbrt x)))))
double code(double x) {
	double tmp;
	if (x <= 48000000.0) {
		tmp = cbrt(((1.0 - (x * x)) * (1.0 / (1.0 - x)))) - cbrt(x);
	} else {
		tmp = 0.3333333333333333 / (x / cbrt(x));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 48000000.0) {
		tmp = Math.cbrt(((1.0 - (x * x)) * (1.0 / (1.0 - x)))) - Math.cbrt(x);
	} else {
		tmp = 0.3333333333333333 / (x / Math.cbrt(x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 48000000.0)
		tmp = Float64(cbrt(Float64(Float64(1.0 - Float64(x * x)) * Float64(1.0 / Float64(1.0 - x)))) - cbrt(x));
	else
		tmp = Float64(0.3333333333333333 / Float64(x / cbrt(x)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 48000000.0], N[(N[Power[N[(N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision], N[(0.3333333333333333 / N[(x / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 48000000:\\
\;\;\;\;\sqrt[3]{\left(1 - x \cdot x\right) \cdot \frac{1}{1 - x}} - \sqrt[3]{x}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4.8e7

    1. Initial program 79.7%

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

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left({\left(\sqrt[3]{x + 1}\right)}^{3}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      2. sqr-powN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left({\left(\sqrt[3]{x + 1}\right)}^{\left(\frac{3}{2}\right)} \cdot {\left(\sqrt[3]{x + 1}\right)}^{\left(\frac{3}{2}\right)}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      3. pow2N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left({\left({\left(\sqrt[3]{x + 1}\right)}^{\left(\frac{3}{2}\right)}\right)}^{2}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      4. pow-lowering-pow.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\left({\left(\sqrt[3]{x + 1}\right)}^{\left(\frac{3}{2}\right)}\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      5. pow1/3N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\left({\left({\left(x + 1\right)}^{\frac{1}{3}}\right)}^{\left(\frac{3}{2}\right)}\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      6. pow-powN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\left({\left(x + 1\right)}^{\left(\frac{1}{3} \cdot \frac{3}{2}\right)}\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      7. pow-lowering-pow.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\mathsf{pow.f64}\left(\left(x + 1\right), \left(\frac{1}{3} \cdot \frac{3}{2}\right)\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\mathsf{pow.f64}\left(\mathsf{+.f64}\left(x, 1\right), \left(\frac{1}{3} \cdot \frac{3}{2}\right)\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\mathsf{pow.f64}\left(\mathsf{+.f64}\left(x, 1\right), \left(\frac{1}{3} \cdot \frac{3}{2}\right)\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      10. metadata-eval79.2%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{pow.f64}\left(\mathsf{pow.f64}\left(\mathsf{+.f64}\left(x, 1\right), \frac{1}{2}\right), 2\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
    4. Applied egg-rr79.2%

      \[\leadsto \sqrt[3]{\color{blue}{{\left({\left(x + 1\right)}^{0.5}\right)}^{2}}} - \sqrt[3]{x} \]
    5. Step-by-step derivation
      1. pow-powN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left({\left(x + 1\right)}^{\left(\frac{1}{2} \cdot 2\right)}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left({\left(x + 1\right)}^{1}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      3. unpow1N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left(x + 1\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      4. +-commutativeN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left(1 + x\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      5. flip-+N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left(\frac{1 \cdot 1 - x \cdot x}{1 - x}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      6. div-invN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\left(\left(1 \cdot 1 - x \cdot x\right) \cdot \frac{1}{1 - x}\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\left(1 \cdot 1 - x \cdot x\right), \left(\frac{1}{1 - x}\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\left(1 - x \cdot x\right), \left(\frac{1}{1 - x}\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      9. --lowering--.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \left(x \cdot x\right)\right), \left(\frac{1}{1 - x}\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right), \left(\frac{1}{1 - x}\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      11. /-lowering-/.f64N/A

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right), \mathsf{/.f64}\left(1, \left(1 - x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
      12. --lowering--.f6480.2%

        \[\leadsto \mathsf{\_.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(\mathsf{\_.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right), \mathsf{/.f64}\left(1, \mathsf{\_.f64}\left(1, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(x\right)\right) \]
    6. Applied egg-rr80.2%

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

    if 4.8e7 < x

    1. Initial program 5.2%

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

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
      4. cbrt-lowering-cbrt.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
      9. *-lowering-*.f6450.4%

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
    5. Simplified50.4%

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

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

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

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

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

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
      6. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
      7. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
      8. pow-sqrN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
      10. pow-lowering-pow.f6489.9%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
    7. Applied egg-rr89.9%

      \[\leadsto \color{blue}{\frac{0.3333333333333333}{{x}^{0.6666666666666666}}} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\frac{-1}{3} + \color{blue}{1}\right)}\right)\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\left(\mathsf{neg}\left(\frac{1}{3}\right)\right) + 1\right)}\right)\right) \]
      3. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\mathsf{neg}\left(\frac{1}{3}\right)\right)} \cdot \color{blue}{x}\right)\right) \]
      4. pow-flipN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{{x}^{\frac{1}{3}}} \cdot x\right)\right) \]
      5. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{\sqrt[3]{x}} \cdot x\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{\sqrt[3]{1}}{\sqrt[3]{x}} \cdot x\right)\right) \]
      7. cbrt-divN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{1}{x}} \cdot x\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \color{blue}{\sqrt[3]{\frac{1}{x}}}\right)\right) \]
      9. cbrt-divN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{\sqrt[3]{1}}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{1}{\sqrt[3]{\color{blue}{x}}}\right)\right) \]
      11. un-div-invN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{x}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
      12. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \color{blue}{\left(\sqrt[3]{x}\right)}\right)\right) \]
      13. cbrt-lowering-cbrt.f6498.6%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \mathsf{cbrt.f64}\left(x\right)\right)\right) \]
    9. Applied egg-rr98.6%

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

Alternative 2: 98.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{0.6666666666666666}{x \cdot \left(\frac{1}{\sqrt[3]{\frac{1}{\frac{1}{x} + \frac{2}{x \cdot x}}}} + \sqrt[3]{\frac{1}{x}}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  0.6666666666666666
  (*
   x
   (+ (/ 1.0 (cbrt (/ 1.0 (+ (/ 1.0 x) (/ 2.0 (* x x)))))) (cbrt (/ 1.0 x))))))
double code(double x) {
	return 0.6666666666666666 / (x * ((1.0 / cbrt((1.0 / ((1.0 / x) + (2.0 / (x * x)))))) + cbrt((1.0 / x))));
}
public static double code(double x) {
	return 0.6666666666666666 / (x * ((1.0 / Math.cbrt((1.0 / ((1.0 / x) + (2.0 / (x * x)))))) + Math.cbrt((1.0 / x))));
}
function code(x)
	return Float64(0.6666666666666666 / Float64(x * Float64(Float64(1.0 / cbrt(Float64(1.0 / Float64(Float64(1.0 / x) + Float64(2.0 / Float64(x * x)))))) + cbrt(Float64(1.0 / x)))))
end
code[x_] := N[(0.6666666666666666 / N[(x * N[(N[(1.0 / N[Power[N[(1.0 / N[(N[(1.0 / x), $MachinePrecision] + N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + N[Power[N[(1.0 / x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.6666666666666666}{x \cdot \left(\frac{1}{\sqrt[3]{\frac{1}{\frac{1}{x} + \frac{2}{x \cdot x}}}} + \sqrt[3]{\frac{1}{x}}\right)}
\end{array}
Derivation
  1. Initial program 8.1%

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\left(\left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) - \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right), \color{blue}{\left(\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right)}\right) \]
  4. Applied egg-rr7.3%

    \[\leadsto \color{blue}{\frac{{\left(x + 1\right)}^{1.3333333333333333} - {x}^{1.3333333333333333}}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left({\left(x + 1\right)}^{0.6666666666666666} + {x}^{0.6666666666666666}\right)}} \]
  5. Taylor expanded in x around inf

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

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \color{blue}{\left(x \cdot \left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)\right)}\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \color{blue}{\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)}\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}}\right), \color{blue}{\left(\sqrt[3]{\frac{1}{x}}\right)}\right)\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\left(\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}\right)\right), \left(\sqrt[3]{\color{blue}{\frac{1}{x}}}\right)\right)\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{x}\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{\color{blue}{1}}{x}}\right)\right)\right)\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    7. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2 \cdot 1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left({x}^{2}\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left(x \cdot x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    12. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\left(\frac{1}{x}\right)\right)\right)\right)\right) \]
    13. /-lowering-/.f6497.5%

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
  7. Simplified97.5%

    \[\leadsto \color{blue}{\frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \sqrt[3]{\frac{1}{x}}\right)}} \]
  8. Step-by-step derivation
    1. flip-+N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\sqrt[3]{\frac{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}{\frac{1}{x} - \frac{2}{x \cdot x}}}\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(\color{blue}{1}, x\right)\right)\right)\right)\right) \]
    2. clear-numN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\sqrt[3]{\frac{1}{\frac{\frac{1}{x} - \frac{2}{x \cdot x}}{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}}}\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(\color{blue}{1}, x\right)\right)\right)\right)\right) \]
    3. cbrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\frac{\sqrt[3]{1}}{\sqrt[3]{\frac{\frac{1}{x} - \frac{2}{x \cdot x}}{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}}}\right), \mathsf{cbrt.f64}\left(\color{blue}{\mathsf{/.f64}\left(1, x\right)}\right)\right)\right)\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\frac{1}{\sqrt[3]{\frac{\frac{1}{x} - \frac{2}{x \cdot x}}{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}}}\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(\color{blue}{1}, x\right)\right)\right)\right)\right) \]
    5. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \left(\sqrt[3]{\frac{\frac{1}{x} - \frac{2}{x \cdot x}}{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}}\right)\right), \mathsf{cbrt.f64}\left(\color{blue}{\mathsf{/.f64}\left(1, x\right)}\right)\right)\right)\right) \]
    6. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(\left(\frac{\frac{1}{x} - \frac{2}{x \cdot x}}{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \color{blue}{x}\right)\right)\right)\right)\right) \]
    7. clear-numN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(\left(\frac{1}{\frac{\frac{1}{x} \cdot \frac{1}{x} - \frac{2}{x \cdot x} \cdot \frac{2}{x \cdot x}}{\frac{1}{x} - \frac{2}{x \cdot x}}}\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
    8. flip-+N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(\left(\frac{1}{\frac{1}{x} + \frac{2}{x \cdot x}}\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(\frac{1}{x} + \frac{2}{x \cdot x}\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
    10. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\left(\frac{1}{x}\right), \left(\frac{2}{x \cdot x}\right)\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
  9. Applied egg-rr97.6%

    \[\leadsto \frac{0.6666666666666666}{x \cdot \left(\color{blue}{\frac{1}{\sqrt[3]{\frac{1}{\frac{1}{x} + \frac{2}{x \cdot x}}}}} + \sqrt[3]{\frac{1}{x}}\right)} \]
  10. Add Preprocessing

Alternative 3: 98.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \frac{1}{\sqrt[3]{x}}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  0.6666666666666666
  (* x (+ (cbrt (+ (/ 1.0 x) (/ 2.0 (* x x)))) (/ 1.0 (cbrt x))))))
double code(double x) {
	return 0.6666666666666666 / (x * (cbrt(((1.0 / x) + (2.0 / (x * x)))) + (1.0 / cbrt(x))));
}
public static double code(double x) {
	return 0.6666666666666666 / (x * (Math.cbrt(((1.0 / x) + (2.0 / (x * x)))) + (1.0 / Math.cbrt(x))));
}
function code(x)
	return Float64(0.6666666666666666 / Float64(x * Float64(cbrt(Float64(Float64(1.0 / x) + Float64(2.0 / Float64(x * x)))) + Float64(1.0 / cbrt(x)))))
end
code[x_] := N[(0.6666666666666666 / N[(x * N[(N[Power[N[(N[(1.0 / x), $MachinePrecision] + N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] + N[(1.0 / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \frac{1}{\sqrt[3]{x}}\right)}
\end{array}
Derivation
  1. Initial program 8.1%

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\left(\left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) - \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right), \color{blue}{\left(\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right)}\right) \]
  4. Applied egg-rr7.3%

    \[\leadsto \color{blue}{\frac{{\left(x + 1\right)}^{1.3333333333333333} - {x}^{1.3333333333333333}}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left({\left(x + 1\right)}^{0.6666666666666666} + {x}^{0.6666666666666666}\right)}} \]
  5. Taylor expanded in x around inf

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

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \color{blue}{\left(x \cdot \left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)\right)}\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \color{blue}{\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)}\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}}\right), \color{blue}{\left(\sqrt[3]{\frac{1}{x}}\right)}\right)\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\left(\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}\right)\right), \left(\sqrt[3]{\color{blue}{\frac{1}{x}}}\right)\right)\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{x}\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{\color{blue}{1}}{x}}\right)\right)\right)\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    7. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2 \cdot 1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left({x}^{2}\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left(x \cdot x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    12. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\left(\frac{1}{x}\right)\right)\right)\right)\right) \]
    13. /-lowering-/.f6497.5%

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
  7. Simplified97.5%

    \[\leadsto \color{blue}{\frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \sqrt[3]{\frac{1}{x}}\right)}} \]
  8. Step-by-step derivation
    1. cbrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\frac{\sqrt[3]{1}}{\color{blue}{\sqrt[3]{x}}}\right)\right)\right)\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\frac{1}{\sqrt[3]{\color{blue}{x}}}\right)\right)\right)\right) \]
    3. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{/.f64}\left(1, \color{blue}{\left(\sqrt[3]{x}\right)}\right)\right)\right)\right) \]
    4. cbrt-lowering-cbrt.f6497.6%

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{/.f64}\left(1, \mathsf{cbrt.f64}\left(x\right)\right)\right)\right)\right) \]
  9. Applied egg-rr97.6%

    \[\leadsto \frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \color{blue}{\frac{1}{\sqrt[3]{x}}}\right)} \]
  10. Add Preprocessing

Alternative 4: 98.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x}} + \sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  0.6666666666666666
  (* x (+ (cbrt (/ 1.0 x)) (cbrt (+ (/ 1.0 x) (/ 2.0 (* x x))))))))
double code(double x) {
	return 0.6666666666666666 / (x * (cbrt((1.0 / x)) + cbrt(((1.0 / x) + (2.0 / (x * x))))));
}
public static double code(double x) {
	return 0.6666666666666666 / (x * (Math.cbrt((1.0 / x)) + Math.cbrt(((1.0 / x) + (2.0 / (x * x))))));
}
function code(x)
	return Float64(0.6666666666666666 / Float64(x * Float64(cbrt(Float64(1.0 / x)) + cbrt(Float64(Float64(1.0 / x) + Float64(2.0 / Float64(x * x)))))))
end
code[x_] := N[(0.6666666666666666 / N[(x * N[(N[Power[N[(1.0 / x), $MachinePrecision], 1/3], $MachinePrecision] + N[Power[N[(N[(1.0 / x), $MachinePrecision] + N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x}} + \sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}}\right)}
\end{array}
Derivation
  1. Initial program 8.1%

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\left(\left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}\right) - \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right), \color{blue}{\left(\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left(\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \sqrt[3]{x} \cdot \sqrt[3]{x}\right)\right)}\right) \]
  4. Applied egg-rr7.3%

    \[\leadsto \color{blue}{\frac{{\left(x + 1\right)}^{1.3333333333333333} - {x}^{1.3333333333333333}}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right) \cdot \left({\left(x + 1\right)}^{0.6666666666666666} + {x}^{0.6666666666666666}\right)}} \]
  5. Taylor expanded in x around inf

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

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \color{blue}{\left(x \cdot \left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)\right)}\right) \]
    2. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \color{blue}{\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}} + \sqrt[3]{\frac{1}{x}}\right)}\right)\right) \]
    3. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\left(\sqrt[3]{\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}}\right), \color{blue}{\left(\sqrt[3]{\frac{1}{x}}\right)}\right)\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\left(\frac{1}{x} + 2 \cdot \frac{1}{{x}^{2}}\right)\right), \left(\sqrt[3]{\color{blue}{\frac{1}{x}}}\right)\right)\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\left(\frac{1}{x}\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{\color{blue}{1}}{x}}\right)\right)\right)\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(2 \cdot \frac{1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    7. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2 \cdot 1}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \left(\frac{2}{{x}^{2}}\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    9. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left({x}^{2}\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \left(x \cdot x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \left(\sqrt[3]{\frac{1}{x}}\right)\right)\right)\right) \]
    12. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\left(\frac{1}{x}\right)\right)\right)\right)\right) \]
    13. /-lowering-/.f6497.5%

      \[\leadsto \mathsf{/.f64}\left(\frac{2}{3}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\mathsf{cbrt.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(1, x\right), \mathsf{/.f64}\left(2, \mathsf{*.f64}\left(x, x\right)\right)\right)\right), \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, x\right)\right)\right)\right)\right) \]
  7. Simplified97.5%

    \[\leadsto \color{blue}{\frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}} + \sqrt[3]{\frac{1}{x}}\right)}} \]
  8. Final simplification97.5%

    \[\leadsto \frac{0.6666666666666666}{x \cdot \left(\sqrt[3]{\frac{1}{x}} + \sqrt[3]{\frac{1}{x} + \frac{2}{x \cdot x}}\right)} \]
  9. Add Preprocessing

Alternative 5: 98.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 39000000:\\ \;\;\;\;\sqrt[3]{x + 1} - \sqrt[3]{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.3333333333333333}{\frac{x}{\sqrt[3]{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 39000000.0)
   (- (cbrt (+ x 1.0)) (cbrt x))
   (/ 0.3333333333333333 (/ x (cbrt x)))))
double code(double x) {
	double tmp;
	if (x <= 39000000.0) {
		tmp = cbrt((x + 1.0)) - cbrt(x);
	} else {
		tmp = 0.3333333333333333 / (x / cbrt(x));
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 39000000.0) {
		tmp = Math.cbrt((x + 1.0)) - Math.cbrt(x);
	} else {
		tmp = 0.3333333333333333 / (x / Math.cbrt(x));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 39000000.0)
		tmp = Float64(cbrt(Float64(x + 1.0)) - cbrt(x));
	else
		tmp = Float64(0.3333333333333333 / Float64(x / cbrt(x)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 39000000.0], N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision], N[(0.3333333333333333 / N[(x / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 39000000:\\
\;\;\;\;\sqrt[3]{x + 1} - \sqrt[3]{x}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.9e7

    1. Initial program 79.7%

      \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
    2. Add Preprocessing

    if 3.9e7 < x

    1. Initial program 5.2%

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

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
      4. cbrt-lowering-cbrt.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
      9. *-lowering-*.f6450.4%

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
    5. Simplified50.4%

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

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

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

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

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

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
      6. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
      7. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
      8. pow-sqrN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
      10. pow-lowering-pow.f6489.9%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
    7. Applied egg-rr89.9%

      \[\leadsto \color{blue}{\frac{0.3333333333333333}{{x}^{0.6666666666666666}}} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\frac{-1}{3} + \color{blue}{1}\right)}\right)\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\left(\mathsf{neg}\left(\frac{1}{3}\right)\right) + 1\right)}\right)\right) \]
      3. pow-plusN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\mathsf{neg}\left(\frac{1}{3}\right)\right)} \cdot \color{blue}{x}\right)\right) \]
      4. pow-flipN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{{x}^{\frac{1}{3}}} \cdot x\right)\right) \]
      5. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{\sqrt[3]{x}} \cdot x\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{\sqrt[3]{1}}{\sqrt[3]{x}} \cdot x\right)\right) \]
      7. cbrt-divN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{1}{x}} \cdot x\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \color{blue}{\sqrt[3]{\frac{1}{x}}}\right)\right) \]
      9. cbrt-divN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{\sqrt[3]{1}}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{1}{\sqrt[3]{\color{blue}{x}}}\right)\right) \]
      11. un-div-invN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{x}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
      12. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \color{blue}{\left(\sqrt[3]{x}\right)}\right)\right) \]
      13. cbrt-lowering-cbrt.f6498.6%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \mathsf{cbrt.f64}\left(x\right)\right)\right) \]
    9. Applied egg-rr98.6%

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

Alternative 6: 92.1% accurate, 1.9× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;\frac{0.3333333333333333}{{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. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
      4. cbrt-lowering-cbrt.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
      9. *-lowering-*.f6493.1%

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
    5. Simplified93.1%

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

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

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

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

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

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
      6. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
      7. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
      8. pow-sqrN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
      10. pow-lowering-pow.f6486.8%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
    7. Applied egg-rr86.8%

      \[\leadsto \color{blue}{\frac{0.3333333333333333}{{x}^{0.6666666666666666}}} \]
    8. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(2 \cdot \color{blue}{\frac{1}{3}}\right)}\right)\right) \]
      2. pow-sqrN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \color{blue}{{x}^{\frac{1}{3}}}\right)\right) \]
      3. unpow-prod-downN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({\left(x \cdot x\right)}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
      4. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\sqrt[3]{x \cdot x}\right)\right) \]
      5. cbrt-lowering-cbrt.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(x \cdot x\right)\right)\right) \]
      6. *-lowering-*.f6493.3%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{*.f64}\left(x, x\right)\right)\right) \]
    9. Applied egg-rr93.3%

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

    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. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
      2. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
      4. cbrt-lowering-cbrt.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
      5. associate-*r/N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
      9. *-lowering-*.f644.7%

        \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
    5. Simplified4.7%

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

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

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

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

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

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
      6. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
      7. pow1/3N/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
      8. pow-sqrN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
      10. pow-lowering-pow.f6489.1%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
    7. Applied egg-rr89.1%

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

Alternative 7: 97.2% accurate, 2.0× speedup?

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

\\
\frac{0.3333333333333333}{\frac{x}{\sqrt[3]{x}}}
\end{array}
Derivation
  1. Initial program 8.1%

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

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
    3. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
    5. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
    8. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
    9. *-lowering-*.f6449.9%

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
  5. Simplified49.9%

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

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
    6. pow1/3N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
    7. pow1/3N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
    8. pow-sqrN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
    10. pow-lowering-pow.f6487.9%

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
  7. Applied egg-rr87.9%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{{x}^{0.6666666666666666}}} \]
  8. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\frac{-1}{3} + \color{blue}{1}\right)}\right)\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\left(\mathsf{neg}\left(\frac{1}{3}\right)\right) + 1\right)}\right)\right) \]
    3. pow-plusN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\left(\mathsf{neg}\left(\frac{1}{3}\right)\right)} \cdot \color{blue}{x}\right)\right) \]
    4. pow-flipN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{{x}^{\frac{1}{3}}} \cdot x\right)\right) \]
    5. pow1/3N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{1}{\sqrt[3]{x}} \cdot x\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{\sqrt[3]{1}}{\sqrt[3]{x}} \cdot x\right)\right) \]
    7. cbrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{1}{x}} \cdot x\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \color{blue}{\sqrt[3]{\frac{1}{x}}}\right)\right) \]
    9. cbrt-divN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{\sqrt[3]{1}}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(x \cdot \frac{1}{\sqrt[3]{\color{blue}{x}}}\right)\right) \]
    11. un-div-invN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left(\frac{x}{\color{blue}{\sqrt[3]{x}}}\right)\right) \]
    12. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \color{blue}{\left(\sqrt[3]{x}\right)}\right)\right) \]
    13. cbrt-lowering-cbrt.f6496.3%

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{/.f64}\left(x, \mathsf{cbrt.f64}\left(x\right)\right)\right) \]
  9. Applied egg-rr96.3%

    \[\leadsto \frac{0.3333333333333333}{\color{blue}{\frac{x}{\sqrt[3]{x}}}} \]
  10. Add Preprocessing

Alternative 8: 88.8% accurate, 2.0× 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 8.1%

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

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
    3. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
    5. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
    8. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
    9. *-lowering-*.f6449.9%

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
  5. Simplified49.9%

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

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

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

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

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

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}\right) \]
    6. pow1/3N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot \sqrt[3]{\color{blue}{x}}\right)\right) \]
    7. pow1/3N/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{1}{3}} \cdot {x}^{\color{blue}{\frac{1}{3}}}\right)\right) \]
    8. pow-sqrN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\color{blue}{\left(2 \cdot \frac{1}{3}\right)}}\right)\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \left({x}^{\frac{2}{3}}\right)\right) \]
    10. pow-lowering-pow.f6487.9%

      \[\leadsto \mathsf{/.f64}\left(\frac{1}{3}, \mathsf{pow.f64}\left(x, \color{blue}{\frac{2}{3}}\right)\right) \]
  7. Applied egg-rr87.9%

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

Alternative 9: 88.8% accurate, 2.0× 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 8.1%

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

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \color{blue}{\left(\sqrt[3]{\frac{1}{{x}^{2}}}\right)}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{\frac{-1 \cdot -1}{{x}^{2}}}\right)\right) \]
    3. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \left(\sqrt[3]{-1 \cdot \frac{-1}{{x}^{2}}}\right)\right) \]
    4. cbrt-lowering-cbrt.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(-1 \cdot \frac{-1}{{x}^{2}}\right)\right)\right) \]
    5. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{-1 \cdot -1}{{x}^{2}}\right)\right)\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\left(\frac{1}{{x}^{2}}\right)\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left({x}^{2}\right)\right)\right)\right) \]
    8. unpow2N/A

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \left(x \cdot x\right)\right)\right)\right) \]
    9. *-lowering-*.f6449.9%

      \[\leadsto \mathsf{*.f64}\left(\frac{1}{3}, \mathsf{cbrt.f64}\left(\mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, x\right)\right)\right)\right) \]
  5. Simplified49.9%

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

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

      \[\leadsto \mathsf{*.f64}\left(\left(\sqrt[3]{\frac{1}{x \cdot x}}\right), \color{blue}{\frac{1}{3}}\right) \]
    3. pow1/3N/A

      \[\leadsto \mathsf{*.f64}\left(\left({\left(\frac{1}{x \cdot x}\right)}^{\frac{1}{3}}\right), \frac{1}{3}\right) \]
    4. inv-powN/A

      \[\leadsto \mathsf{*.f64}\left(\left({\left({\left(x \cdot x\right)}^{-1}\right)}^{\frac{1}{3}}\right), \frac{1}{3}\right) \]
    5. pow-powN/A

      \[\leadsto \mathsf{*.f64}\left(\left({\left(x \cdot x\right)}^{\left(-1 \cdot \frac{1}{3}\right)}\right), \frac{1}{3}\right) \]
    6. pow2N/A

      \[\leadsto \mathsf{*.f64}\left(\left({\left({x}^{2}\right)}^{\left(-1 \cdot \frac{1}{3}\right)}\right), \frac{1}{3}\right) \]
    7. pow-powN/A

      \[\leadsto \mathsf{*.f64}\left(\left({x}^{\left(2 \cdot \left(-1 \cdot \frac{1}{3}\right)\right)}\right), \frac{1}{3}\right) \]
    8. pow-lowering-pow.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \left(2 \cdot \left(-1 \cdot \frac{1}{3}\right)\right)\right), \frac{1}{3}\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \left(2 \cdot \frac{-1}{3}\right)\right), \frac{1}{3}\right) \]
    10. metadata-eval87.9%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{pow.f64}\left(x, \frac{-2}{3}\right), \frac{1}{3}\right) \]
  7. Applied egg-rr87.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  8. Final simplification87.9%

    \[\leadsto 0.3333333333333333 \cdot {x}^{-0.6666666666666666} \]
  9. 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 8.1%

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

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

      \[\leadsto \mathsf{\_.f64}\left(1, \color{blue}{\left(\sqrt[3]{x}\right)}\right) \]
    2. cbrt-lowering-cbrt.f641.8%

      \[\leadsto \mathsf{\_.f64}\left(1, \mathsf{cbrt.f64}\left(x\right)\right) \]
  5. Simplified1.8%

    \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
  6. 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 2024158 
(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)))