2cbrt (problem 3.3.4)

Percentage Accurate: 6.9% → 97.5%
Time: 3.3s
Alternatives: 12
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}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 12 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 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: 97.5% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sqrt[3]{x}}\\ \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, t\_0 \cdot \left(t\_0 \cdot 0.3333333333333333\right)\right) \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ 1.0 (cbrt x))))
   (fma
    (pow x -1.6666666666666667)
    -0.1111111111111111
    (* t_0 (* t_0 0.3333333333333333)))))
double code(double x) {
	double t_0 = 1.0 / cbrt(x);
	return fma(pow(x, -1.6666666666666667), -0.1111111111111111, (t_0 * (t_0 * 0.3333333333333333)));
}
function code(x)
	t_0 = Float64(1.0 / cbrt(x))
	return fma((x ^ -1.6666666666666667), -0.1111111111111111, Float64(t_0 * Float64(t_0 * 0.3333333333333333)))
end
code[x_] := Block[{t$95$0 = N[(1.0 / N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]}, N[(N[Power[x, -1.6666666666666667], $MachinePrecision] * -0.1111111111111111 + N[(t$95$0 * N[(t$95$0 * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{\sqrt[3]{x}}\\
\mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, t\_0 \cdot \left(t\_0 \cdot 0.3333333333333333\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 6.9%

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

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

      \[\leadsto \frac{\frac{-1}{9} \cdot \sqrt[3]{x} + \frac{1}{3} \cdot \sqrt[3]{{x}^{4}}}{\color{blue}{{x}^{2}}} \]
    2. +-commutativeN/A

      \[\leadsto \frac{\frac{1}{3} \cdot \sqrt[3]{{x}^{4}} + \frac{-1}{9} \cdot \sqrt[3]{x}}{{\color{blue}{x}}^{2}} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\sqrt[3]{{x}^{4}} \cdot \frac{1}{3} + \frac{-1}{9} \cdot \sqrt[3]{x}}{{x}^{2}} \]
    4. lower-fma.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left(\sqrt[3]{{x}^{4}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{\color{blue}{x}}^{2}} \]
    5. pow1/3N/A

      \[\leadsto \frac{\mathsf{fma}\left({\left({x}^{4}\right)}^{\frac{1}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    6. pow-powN/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\left(4 \cdot \frac{1}{3}\right)}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    7. lower-pow.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\left(4 \cdot \frac{1}{3}\right)}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    8. metadata-evalN/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    10. lift-cbrt.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    11. unpow2N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{x \cdot \color{blue}{x}} \]
    12. lower-*.f6446.0

      \[\leadsto \frac{\mathsf{fma}\left({x}^{1.3333333333333333}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)}{x \cdot \color{blue}{x}} \]
  4. Applied rewrites46.0%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left({x}^{1.3333333333333333}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)}{x \cdot x}} \]
  5. Taylor expanded in x around inf

    \[\leadsto \frac{-1}{9} \cdot \sqrt[3]{\frac{1}{{x}^{5}}} + \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  6. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{5}}} \cdot \frac{-1}{9} + \frac{1}{3} \cdot \sqrt[3]{\color{blue}{\frac{1}{{x}^{2}}}} \]
    2. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\sqrt[3]{\frac{1}{{x}^{5}}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    3. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({\left(\frac{1}{{x}^{5}}\right)}^{\frac{1}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    4. pow-flipN/A

      \[\leadsto \mathsf{fma}\left({\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    5. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(-5 \cdot \frac{1}{3}\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot -5\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot \left(\mathsf{neg}\left(5\right)\right)\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    10. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot \left(\mathsf{neg}\left(5\right)\right)\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot -5\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    13. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {\left(\frac{1}{{x}^{2}}\right)}^{\frac{1}{3}}\right) \]
    14. pow-flipN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {\left({x}^{\left(\mathsf{neg}\left(2\right)\right)}\right)}^{\frac{1}{3}}\right) \]
    15. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\left(\left(\mathsf{neg}\left(2\right)\right) \cdot \frac{1}{3}\right)}\right) \]
    16. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\left(-2 \cdot \frac{1}{3}\right)}\right) \]
    17. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\frac{-2}{3}}\right) \]
    18. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\frac{-2}{3}}\right) \]
    19. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\frac{-2}{3}} \cdot \frac{1}{3}\right) \]
    20. lift-*.f6489.8

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {x}^{-0.6666666666666666} \cdot 0.3333333333333333\right) \]
  7. Applied rewrites89.8%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, \color{blue}{-0.1111111111111111}, {x}^{-0.6666666666666666} \cdot 0.3333333333333333\right) \]
  8. Step-by-step derivation
    1. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\frac{-2}{3}} \cdot \frac{1}{3}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\left(\frac{2}{3} \cdot -1\right)} \cdot \frac{1}{3}\right) \]
    3. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\frac{2}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\left(2 \cdot \frac{1}{3}\right)}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    5. pow-sqrN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\frac{1}{3}} \cdot {x}^{\frac{1}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    6. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x} \cdot {x}^{\frac{1}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    7. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    8. unpow-prod-downN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    9. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    10. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    11. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    12. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    13. lift-cbrt.f6497.5

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot 0.3333333333333333\right) \]
  9. Applied rewrites97.5%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot 0.3333333333333333\right) \]
  10. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    2. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    3. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{-1} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    4. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{-1} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    5. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{-1} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    6. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{-1} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    7. unpow-1N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    8. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    9. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    10. lower-*.f6497.5

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot 0.3333333333333333\right)\right) \]
    11. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    12. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right)\right) \]
    13. unpow-1N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{3}\right)\right) \]
    14. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot \frac{1}{3}\right)\right) \]
    15. lift-cbrt.f6497.5

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot 0.3333333333333333\right)\right) \]
  11. Applied rewrites97.5%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \frac{1}{\sqrt[3]{x}} \cdot \left(\frac{1}{\sqrt[3]{x}} \cdot 0.3333333333333333\right)\right) \]
  12. Add Preprocessing

Alternative 2: 97.5% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (fma
  (pow x -1.6666666666666667)
  -0.1111111111111111
  (* (pow (cbrt x) -2.0) 0.3333333333333333)))
double code(double x) {
	return fma(pow(x, -1.6666666666666667), -0.1111111111111111, (pow(cbrt(x), -2.0) * 0.3333333333333333));
}
function code(x)
	return fma((x ^ -1.6666666666666667), -0.1111111111111111, Float64((cbrt(x) ^ -2.0) * 0.3333333333333333))
end
code[x_] := N[(N[Power[x, -1.6666666666666667], $MachinePrecision] * -0.1111111111111111 + N[(N[Power[N[Power[x, 1/3], $MachinePrecision], -2.0], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333\right)
\end{array}
Derivation
  1. Initial program 6.9%

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

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

      \[\leadsto \frac{\frac{-1}{9} \cdot \sqrt[3]{x} + \frac{1}{3} \cdot \sqrt[3]{{x}^{4}}}{\color{blue}{{x}^{2}}} \]
    2. +-commutativeN/A

      \[\leadsto \frac{\frac{1}{3} \cdot \sqrt[3]{{x}^{4}} + \frac{-1}{9} \cdot \sqrt[3]{x}}{{\color{blue}{x}}^{2}} \]
    3. *-commutativeN/A

      \[\leadsto \frac{\sqrt[3]{{x}^{4}} \cdot \frac{1}{3} + \frac{-1}{9} \cdot \sqrt[3]{x}}{{x}^{2}} \]
    4. lower-fma.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left(\sqrt[3]{{x}^{4}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{\color{blue}{x}}^{2}} \]
    5. pow1/3N/A

      \[\leadsto \frac{\mathsf{fma}\left({\left({x}^{4}\right)}^{\frac{1}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    6. pow-powN/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\left(4 \cdot \frac{1}{3}\right)}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    7. lower-pow.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\left(4 \cdot \frac{1}{3}\right)}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    8. metadata-evalN/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    10. lift-cbrt.f64N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{{x}^{2}} \]
    11. unpow2N/A

      \[\leadsto \frac{\mathsf{fma}\left({x}^{\frac{4}{3}}, \frac{1}{3}, \frac{-1}{9} \cdot \sqrt[3]{x}\right)}{x \cdot \color{blue}{x}} \]
    12. lower-*.f6446.0

      \[\leadsto \frac{\mathsf{fma}\left({x}^{1.3333333333333333}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)}{x \cdot \color{blue}{x}} \]
  4. Applied rewrites46.0%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left({x}^{1.3333333333333333}, 0.3333333333333333, -0.1111111111111111 \cdot \sqrt[3]{x}\right)}{x \cdot x}} \]
  5. Taylor expanded in x around inf

    \[\leadsto \frac{-1}{9} \cdot \sqrt[3]{\frac{1}{{x}^{5}}} + \color{blue}{\frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  6. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \sqrt[3]{\frac{1}{{x}^{5}}} \cdot \frac{-1}{9} + \frac{1}{3} \cdot \sqrt[3]{\color{blue}{\frac{1}{{x}^{2}}}} \]
    2. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\sqrt[3]{\frac{1}{{x}^{5}}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    3. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({\left(\frac{1}{{x}^{5}}\right)}^{\frac{1}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    4. pow-flipN/A

      \[\leadsto \mathsf{fma}\left({\left({x}^{\left(\mathsf{neg}\left(5\right)\right)}\right)}^{\frac{1}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    5. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\left(\mathsf{neg}\left(5\right)\right) \cdot \frac{1}{3}\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    6. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(-5 \cdot \frac{1}{3}\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot -5\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    9. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot \left(\mathsf{neg}\left(5\right)\right)\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    10. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot \left(\mathsf{neg}\left(5\right)\right)\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\left(\frac{1}{3} \cdot -5\right)}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) \]
    13. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {\left(\frac{1}{{x}^{2}}\right)}^{\frac{1}{3}}\right) \]
    14. pow-flipN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {\left({x}^{\left(\mathsf{neg}\left(2\right)\right)}\right)}^{\frac{1}{3}}\right) \]
    15. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\left(\left(\mathsf{neg}\left(2\right)\right) \cdot \frac{1}{3}\right)}\right) \]
    16. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\left(-2 \cdot \frac{1}{3}\right)}\right) \]
    17. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\frac{-2}{3}}\right) \]
    18. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \frac{1}{3} \cdot {x}^{\frac{-2}{3}}\right) \]
    19. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\frac{-2}{3}} \cdot \frac{1}{3}\right) \]
    20. lift-*.f6489.8

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {x}^{-0.6666666666666666} \cdot 0.3333333333333333\right) \]
  7. Applied rewrites89.8%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, \color{blue}{-0.1111111111111111}, {x}^{-0.6666666666666666} \cdot 0.3333333333333333\right) \]
  8. Step-by-step derivation
    1. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\frac{-2}{3}} \cdot \frac{1}{3}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {x}^{\left(\frac{2}{3} \cdot -1\right)} \cdot \frac{1}{3}\right) \]
    3. pow-powN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\frac{2}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    4. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\left(2 \cdot \frac{1}{3}\right)}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    5. pow-sqrN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left({x}^{\frac{1}{3}} \cdot {x}^{\frac{1}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    6. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x} \cdot {x}^{\frac{1}{3}}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    7. pow1/3N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right)}^{-1} \cdot \frac{1}{3}\right) \]
    8. unpow-prod-downN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    9. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    10. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    11. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    12. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    13. lift-cbrt.f6497.5

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot 0.3333333333333333\right) \]
  9. Applied rewrites97.5%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot 0.3333333333333333\right) \]
  10. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    2. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    3. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    4. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    5. lift-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, \left({\left(\sqrt[3]{x}\right)}^{-1} \cdot {\left(\sqrt[3]{x}\right)}^{-1}\right) \cdot \frac{1}{3}\right) \]
    6. pow-prod-upN/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{\left(-1 + -1\right)} \cdot \frac{1}{3}\right) \]
    7. lower-pow.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{\left(-1 + -1\right)} \cdot \frac{1}{3}\right) \]
    8. lift-cbrt.f64N/A

      \[\leadsto \mathsf{fma}\left({x}^{\frac{-5}{3}}, \frac{-1}{9}, {\left(\sqrt[3]{x}\right)}^{\left(-1 + -1\right)} \cdot \frac{1}{3}\right) \]
    9. metadata-eval97.5

      \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333\right) \]
  11. Applied rewrites97.5%

    \[\leadsto \mathsf{fma}\left({x}^{-1.6666666666666667}, -0.1111111111111111, {\left(\sqrt[3]{x}\right)}^{-2} \cdot 0.3333333333333333\right) \]
  12. Add Preprocessing

Alternative 3: 96.5% accurate, 0.9× speedup?

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

\\
\frac{-1}{\sqrt[3]{-x}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}}
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    12. metadata-eval88.9

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  4. Applied rewrites88.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  5. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
    14. pow2N/A

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

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

      \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
    17. lower-neg.f6450.4

      \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot 0.3333333333333333 \]
  6. Applied rewrites50.4%

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{-1 \cdot \frac{1}{3}}{\sqrt[3]{\mathsf{neg}\left(x\right)} \cdot \sqrt[3]{x}} \]
    10. mul-1-negN/A

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

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

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

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

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

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

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

      \[\leadsto \frac{-1}{\sqrt[3]{-1 \cdot x}} \cdot \frac{\frac{1}{3}}{\sqrt[3]{x}} \]
    18. mul-1-negN/A

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

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

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

      \[\leadsto \frac{-1}{\sqrt[3]{-x}} \cdot \frac{\frac{1}{3}}{\color{blue}{\sqrt[3]{x}}} \]
    22. lift-cbrt.f6496.5

      \[\leadsto \frac{-1}{\sqrt[3]{-x}} \cdot \frac{0.3333333333333333}{\sqrt[3]{x}} \]
  8. Applied rewrites96.5%

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

Alternative 4: 96.5% accurate, 0.9× speedup?

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

\\
\frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    12. metadata-eval88.9

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  4. Applied rewrites88.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  5. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    9. pow2N/A

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
    18. metadata-eval88.9

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  6. Applied rewrites88.9%

    \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  7. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot \frac{1}{3} \]
    8. lift-cbrt.f6496.5

      \[\leadsto \frac{1}{\sqrt[3]{x} \cdot \sqrt[3]{x}} \cdot 0.3333333333333333 \]
  8. Applied rewrites96.5%

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

Alternative 5: 96.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \end{array} \]
(FPCore (x)
 :precision binary64
 (* (/ 1.0 (pow (cbrt x) 2.0)) 0.3333333333333333))
double code(double x) {
	return (1.0 / pow(cbrt(x), 2.0)) * 0.3333333333333333;
}
public static double code(double x) {
	return (1.0 / Math.pow(Math.cbrt(x), 2.0)) * 0.3333333333333333;
}
function code(x)
	return Float64(Float64(1.0 / (cbrt(x) ^ 2.0)) * 0.3333333333333333)
end
code[x_] := N[(N[(1.0 / N[Power[N[Power[x, 1/3], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    12. metadata-eval88.9

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  4. Applied rewrites88.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  5. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
    9. pow2N/A

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
    18. metadata-eval88.9

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  6. Applied rewrites88.9%

    \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
  7. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

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

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

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

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

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot \frac{1}{3} \]
    8. lift-cbrt.f6496.5

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  8. Applied rewrites96.5%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{x}\right)}^{2}} \cdot 0.3333333333333333 \]
  9. Add Preprocessing

Alternative 6: 92.6% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.35 \cdot 10^{+154}:\\ \;\;\;\;\frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot 0.3333333333333333\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.35e+154)
   (* (/ 1.0 (cbrt (* x x))) 0.3333333333333333)
   (* (/ 1.0 (exp (/ (* (log x) 2.0) 3.0))) 0.3333333333333333)))
double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = (1.0 / cbrt((x * x))) * 0.3333333333333333;
	} else {
		tmp = (1.0 / exp(((log(x) * 2.0) / 3.0))) * 0.3333333333333333;
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 1.35e+154) {
		tmp = (1.0 / Math.cbrt((x * x))) * 0.3333333333333333;
	} else {
		tmp = (1.0 / Math.exp(((Math.log(x) * 2.0) / 3.0))) * 0.3333333333333333;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.35e+154)
		tmp = Float64(Float64(1.0 / cbrt(Float64(x * x))) * 0.3333333333333333);
	else
		tmp = Float64(Float64(1.0 / exp(Float64(Float64(log(x) * 2.0) / 3.0))) * 0.3333333333333333);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.35e+154], N[(N[(1.0 / N[Power[N[(x * x), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision], N[(N[(1.0 / N[Exp[N[(N[(N[Log[x], $MachinePrecision] * 2.0), $MachinePrecision] / 3.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]]
\begin{array}{l}

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

\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot 0.3333333333333333\\


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

    1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
      12. metadata-eval88.6

        \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
    4. Applied rewrites88.6%

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      9. pow2N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
      18. metadata-eval88.6

        \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    6. Applied rewrites88.6%

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    7. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. pow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      7. lift-*.f6495.2

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333 \]
    8. Applied rewrites95.2%

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

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      9. pow2N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
      18. metadata-eval89.1

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

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    7. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{e^{\log x \cdot 2}}} \cdot \frac{1}{3} \]
      6. exp-cbrt-revN/A

        \[\leadsto \frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot \frac{1}{3} \]
      7. lower-exp.f64N/A

        \[\leadsto \frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot \frac{1}{3} \]
      8. lower-/.f64N/A

        \[\leadsto \frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot \frac{1}{3} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot \frac{1}{3} \]
      10. lift-log.f6490.0

        \[\leadsto \frac{1}{e^{\frac{\log x \cdot 2}{3}}} \cdot 0.3333333333333333 \]
    8. Applied rewrites90.0%

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

Alternative 7: 92.4% accurate, 1.2× speedup?

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

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

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


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

    1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
      12. metadata-eval88.6

        \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
    4. Applied rewrites88.6%

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      9. pow2N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
      18. metadata-eval88.6

        \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    6. Applied rewrites88.6%

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    7. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. pow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      7. lift-*.f6495.2

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333 \]
    8. Applied rewrites95.2%

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

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      9. pow2N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
      18. metadata-eval89.1

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

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    7. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto \frac{1}{{x}^{\frac{2}{3}}} \cdot \frac{1}{3} \]
      2. pow-to-expN/A

        \[\leadsto \frac{1}{e^{\log x \cdot \frac{2}{3}}} \cdot \frac{1}{3} \]
      3. lower-exp.f64N/A

        \[\leadsto \frac{1}{e^{\log x \cdot \frac{2}{3}}} \cdot \frac{1}{3} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{e^{\log x \cdot \frac{2}{3}}} \cdot \frac{1}{3} \]
      5. lift-log.f6489.6

        \[\leadsto \frac{1}{e^{\log x \cdot 0.6666666666666666}} \cdot 0.3333333333333333 \]
    8. Applied rewrites89.6%

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

Alternative 8: 92.4% accurate, 1.3× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333\\


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

    1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
      12. metadata-eval88.6

        \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
    4. Applied rewrites88.6%

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      9. pow2N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{{x}^{\left(\frac{\frac{4}{3}}{2}\right)}} \cdot \frac{1}{3} \]
      18. metadata-eval88.6

        \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    6. Applied rewrites88.6%

      \[\leadsto \frac{1}{{x}^{0.6666666666666666}} \cdot 0.3333333333333333 \]
    7. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

        \[\leadsto \frac{1}{\sqrt[3]{{x}^{2}}} \cdot \frac{1}{3} \]
      6. pow2N/A

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot \frac{1}{3} \]
      7. lift-*.f6495.2

        \[\leadsto \frac{1}{\sqrt[3]{x \cdot x}} \cdot 0.3333333333333333 \]
    8. Applied rewrites95.2%

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

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto {x}^{\frac{-2}{3}} \cdot \frac{1}{3} \]
      2. pow-to-expN/A

        \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
      3. lower-exp.f64N/A

        \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
      4. lower-*.f64N/A

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

        \[\leadsto e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333 \]
    6. Applied rewrites89.6%

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

Alternative 9: 92.4% accurate, 1.3× speedup?

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

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

\mathbf{else}:\\
\;\;\;\;e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333\\


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

    1. Initial program 9.0%

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
      12. metadata-eval88.6

        \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
    4. Applied rewrites88.6%

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{-1}{\sqrt[3]{\mathsf{neg}\left({x}^{2}\right)}} \cdot \frac{1}{3} \]
      14. pow2N/A

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

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

        \[\leadsto \frac{-1}{\sqrt[3]{\left(\mathsf{neg}\left(x\right)\right) \cdot x}} \cdot \frac{1}{3} \]
      17. lower-neg.f6495.2

        \[\leadsto \frac{-1}{\sqrt[3]{\left(-x\right) \cdot x}} \cdot 0.3333333333333333 \]
    6. Applied rewrites95.2%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\frac{-1}{3}}{\sqrt[3]{\left(-x\right) \cdot x}} \]
      11. lift-cbrt.f6495.2

        \[\leadsto \frac{-0.3333333333333333}{\sqrt[3]{\left(-x\right) \cdot x}} \]
    8. Applied rewrites95.2%

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

    if 1.35000000000000003e154 < x

    1. Initial program 4.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
    5. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto {x}^{\frac{-2}{3}} \cdot \frac{1}{3} \]
      2. pow-to-expN/A

        \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
      3. lower-exp.f64N/A

        \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
      4. lower-*.f64N/A

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

        \[\leadsto e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333 \]
    6. Applied rewrites89.6%

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

Alternative 10: 89.2% accurate, 1.6× speedup?

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

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

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

\\
e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    12. metadata-eval88.9

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  4. Applied rewrites88.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  5. Step-by-step derivation
    1. lift-pow.f64N/A

      \[\leadsto {x}^{\frac{-2}{3}} \cdot \frac{1}{3} \]
    2. pow-to-expN/A

      \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
    3. lower-exp.f64N/A

      \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
    4. lower-*.f64N/A

      \[\leadsto e^{\log x \cdot \frac{-2}{3}} \cdot \frac{1}{3} \]
    5. lower-log.f6489.2

      \[\leadsto e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333 \]
  6. Applied rewrites89.2%

    \[\leadsto e^{\log x \cdot -0.6666666666666666} \cdot 0.3333333333333333 \]
  7. Add Preprocessing

Alternative 11: 88.9% accurate, 1.9× speedup?

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

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

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

\\
{x}^{-0.6666666666666666} \cdot 0.3333333333333333
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto {x}^{\left(\frac{1}{3} \cdot -2\right)} \cdot \frac{1}{3} \]
    12. metadata-eval88.9

      \[\leadsto {x}^{-0.6666666666666666} \cdot 0.3333333333333333 \]
  4. Applied rewrites88.9%

    \[\leadsto \color{blue}{{x}^{-0.6666666666666666} \cdot 0.3333333333333333} \]
  5. Add Preprocessing

Alternative 12: 1.8% accurate, 2.0× speedup?

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

\\
1 - \sqrt[3]{x}
\end{array}
Derivation
  1. Initial program 6.9%

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

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

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

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

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

    Reproduce

    ?
    herbie shell --seed 2025115 
    (FPCore (x)
      :name "2cbrt (problem 3.3.4)"
      :precision binary64
      :pre (and (> x 1.0) (< x 1e+308))
    
      :alt
      (! :herbie-platform c (/ 1 (+ (* (cbrt (+ x 1)) (cbrt (+ x 1))) (* (cbrt x) (cbrt (+ x 1))) (* (cbrt x) (cbrt x)))))
    
      (- (cbrt (+ x 1.0)) (cbrt x)))