Radioactive exchange between two surfaces

Percentage Accurate: 85.9% → 99.9%
Time: 10.2s
Alternatives: 6
Speedup: 7.4×

Specification

?
\[\begin{array}{l} \\ {x}^{4} - {y}^{4} \end{array} \]
(FPCore (x y) :precision binary64 (- (pow x 4.0) (pow y 4.0)))
double code(double x, double y) {
	return pow(x, 4.0) - pow(y, 4.0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x ** 4.0d0) - (y ** 4.0d0)
end function
public static double code(double x, double y) {
	return Math.pow(x, 4.0) - Math.pow(y, 4.0);
}
def code(x, y):
	return math.pow(x, 4.0) - math.pow(y, 4.0)
function code(x, y)
	return Float64((x ^ 4.0) - (y ^ 4.0))
end
function tmp = code(x, y)
	tmp = (x ^ 4.0) - (y ^ 4.0);
end
code[x_, y_] := N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{x}^{4} - {y}^{4}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 6 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: 85.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ {x}^{4} - {y}^{4} \end{array} \]
(FPCore (x y) :precision binary64 (- (pow x 4.0) (pow y 4.0)))
double code(double x, double y) {
	return pow(x, 4.0) - pow(y, 4.0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x ** 4.0d0) - (y ** 4.0d0)
end function
public static double code(double x, double y) {
	return Math.pow(x, 4.0) - Math.pow(y, 4.0);
}
def code(x, y):
	return math.pow(x, 4.0) - math.pow(y, 4.0)
function code(x, y)
	return Float64((x ^ 4.0) - (y ^ 4.0))
end
function tmp = code(x, y)
	tmp = (x ^ 4.0) - (y ^ 4.0);
end
code[x_, y_] := N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{x}^{4} - {y}^{4}
\end{array}

Alternative 1: 99.9% accurate, 7.4× speedup?

\[\begin{array}{l} \\ \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right) \end{array} \]
(FPCore (x y) :precision binary64 (* (+ x y) (* (- x y) (fma x x (* y y)))))
double code(double x, double y) {
	return (x + y) * ((x - y) * fma(x, x, (y * y)));
}
function code(x, y)
	return Float64(Float64(x + y) * Float64(Float64(x - y) * fma(x, x, Float64(y * y))))
end
code[x_, y_] := N[(N[(x + y), $MachinePrecision] * N[(N[(x - y), $MachinePrecision] * N[(x * x + N[(y * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)
\end{array}
Derivation
  1. Initial program 85.5%

    \[{x}^{4} - {y}^{4} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. sqr-powN/A

      \[\leadsto \color{blue}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)}} - {y}^{4} \]
    2. sqr-powN/A

      \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
    3. difference-of-squaresN/A

      \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
    4. lower-*.f64N/A

      \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
    5. metadata-evalN/A

      \[\leadsto \left({x}^{\color{blue}{2}} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    6. unpow2N/A

      \[\leadsto \left(\color{blue}{x \cdot x} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    7. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, {y}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    8. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(x, x, {y}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    10. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    11. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
    13. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
    14. unpow2N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
    15. difference-of-squaresN/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    16. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    17. lower-+.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
    18. lower--.f6499.8

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
  4. Applied rewrites99.8%

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

      \[\leadsto \left(x \cdot x + \color{blue}{y \cdot y}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
    2. lift-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
    3. lift-+.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
    4. lift--.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
    5. lift-*.f64N/A

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    6. *-commutativeN/A

      \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)} \]
    7. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \cdot \mathsf{fma}\left(x, x, y \cdot y\right) \]
    8. associate-*l*N/A

      \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
    9. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
    10. lower-*.f6499.9

      \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
  6. Applied rewrites99.9%

    \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
  7. Add Preprocessing

Alternative 2: 99.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ \mathbf{if}\;t\_0 \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (pow x 4.0) (pow y 4.0))))
   (if (<= t_0 -4e-266)
     (- (* (* y y) (* y y)))
     (if (<= t_0 INFINITY)
       (* x (* x (* x x)))
       (* (* y y) (* (+ x y) (- x y)))))))
double code(double x, double y) {
	double t_0 = pow(x, 4.0) - pow(y, 4.0);
	double tmp;
	if (t_0 <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else if (t_0 <= ((double) INFINITY)) {
		tmp = x * (x * (x * x));
	} else {
		tmp = (y * y) * ((x + y) * (x - y));
	}
	return tmp;
}
public static double code(double x, double y) {
	double t_0 = Math.pow(x, 4.0) - Math.pow(y, 4.0);
	double tmp;
	if (t_0 <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else if (t_0 <= Double.POSITIVE_INFINITY) {
		tmp = x * (x * (x * x));
	} else {
		tmp = (y * y) * ((x + y) * (x - y));
	}
	return tmp;
}
def code(x, y):
	t_0 = math.pow(x, 4.0) - math.pow(y, 4.0)
	tmp = 0
	if t_0 <= -4e-266:
		tmp = -((y * y) * (y * y))
	elif t_0 <= math.inf:
		tmp = x * (x * (x * x))
	else:
		tmp = (y * y) * ((x + y) * (x - y))
	return tmp
function code(x, y)
	t_0 = Float64((x ^ 4.0) - (y ^ 4.0))
	tmp = 0.0
	if (t_0 <= -4e-266)
		tmp = Float64(-Float64(Float64(y * y) * Float64(y * y)));
	elseif (t_0 <= Inf)
		tmp = Float64(x * Float64(x * Float64(x * x)));
	else
		tmp = Float64(Float64(y * y) * Float64(Float64(x + y) * Float64(x - y)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (x ^ 4.0) - (y ^ 4.0);
	tmp = 0.0;
	if (t_0 <= -4e-266)
		tmp = -((y * y) * (y * y));
	elseif (t_0 <= Inf)
		tmp = x * (x * (x * x));
	else
		tmp = (y * y) * ((x + y) * (x - y));
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -4e-266], (-N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]), If[LessEqual[t$95$0, Infinity], N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(y * y), $MachinePrecision] * N[(N[(x + y), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {x}^{4} - {y}^{4}\\
\mathbf{if}\;t\_0 \leq -4 \cdot 10^{-266}:\\
\;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\

\mathbf{elif}\;t\_0 \leq \infty:\\
\;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < -3.9999999999999999e-266

    1. Initial program 100.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
      2. lift-pow.f64N/A

        \[\leadsto {x}^{4} - \color{blue}{{y}^{4}} \]
      3. flip--N/A

        \[\leadsto \color{blue}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      5. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      6. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}}}} \]
      7. flip--N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      8. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      9. lower-/.f6499.9

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{{x}^{4} - {y}^{4}}}} \]
      10. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      11. lift-pow.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4}} - {y}^{4}}} \]
      12. sqr-powN/A

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

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{4}}}} \]
      14. sqr-powN/A

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}}}} \]
      15. difference-of-squaresN/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
      16. lower-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{{y}^{2}} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    6. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
      2. lower-*.f6498.9

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    7. Applied rewrites98.9%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

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

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

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right)}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      6. unpow1N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{\left(\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\right)}^{1}}}} \]
      7. pow-flipN/A

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

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

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      10. remove-double-div98.9

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      11. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      12. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
      13. lower-*.f6498.9

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    9. Applied rewrites98.9%

      \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    10. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\left(-1 \cdot {y}^{2}\right)} \cdot \left(y \cdot y\right) \]
    11. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \left(-1 \cdot \color{blue}{\left(y \cdot y\right)}\right) \cdot \left(y \cdot y\right) \]
      2. associate-*r*N/A

        \[\leadsto \color{blue}{\left(\left(-1 \cdot y\right) \cdot y\right)} \cdot \left(y \cdot y\right) \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      5. mul-1-negN/A

        \[\leadsto \left(y \cdot \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot \left(y \cdot y\right) \]
      6. lower-neg.f6499.1

        \[\leadsto \left(y \cdot \color{blue}{\left(-y\right)}\right) \cdot \left(y \cdot y\right) \]
    12. Applied rewrites99.1%

      \[\leadsto \color{blue}{\left(y \cdot \left(-y\right)\right)} \cdot \left(y \cdot y\right) \]

    if -3.9999999999999999e-266 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < +inf.0

    1. Initial program 100.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{{x}^{4}} \]
    4. Step-by-step derivation
      1. lower-pow.f64100.0

        \[\leadsto \color{blue}{{x}^{4}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{{x}^{4}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto {x}^{\color{blue}{\left(3 + 1\right)}} \]
      2. pow-plusN/A

        \[\leadsto \color{blue}{{x}^{3} \cdot x} \]
      3. cube-unmultN/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
      4. lift-*.f64N/A

        \[\leadsto \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot x \]
      5. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
      6. lower-*.f6499.9

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]
    7. Applied rewrites99.9%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]

    if +inf.0 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

    1. Initial program 0.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sqr-powN/A

        \[\leadsto \color{blue}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)}} - {y}^{4} \]
      2. sqr-powN/A

        \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
      3. difference-of-squaresN/A

        \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
      5. metadata-evalN/A

        \[\leadsto \left({x}^{\color{blue}{2}} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      6. unpow2N/A

        \[\leadsto \left(\color{blue}{x \cdot x} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      7. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, {y}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, {y}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      10. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      12. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      13. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
      14. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
      15. difference-of-squaresN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      16. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      17. lower-+.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
      18. lower--.f64100.0

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{{y}^{2}} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
    6. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
      2. lower-*.f64100.0

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
    7. Applied rewrites100.0%

      \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
  3. Recombined 3 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{elif}\;{x}^{4} - {y}^{4} \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 95.3% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + y\right) \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- (pow x 4.0) (pow y 4.0)) -4e-266)
   (- (* (* y y) (* y y)))
   (* (+ x y) (* x (* x x)))))
double code(double x, double y) {
	double tmp;
	if ((pow(x, 4.0) - pow(y, 4.0)) <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else {
		tmp = (x + y) * (x * (x * x));
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (((x ** 4.0d0) - (y ** 4.0d0)) <= (-4d-266)) then
        tmp = -((y * y) * (y * y))
    else
        tmp = (x + y) * (x * (x * x))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((Math.pow(x, 4.0) - Math.pow(y, 4.0)) <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else {
		tmp = (x + y) * (x * (x * x));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -4e-266:
		tmp = -((y * y) * (y * y))
	else:
		tmp = (x + y) * (x * (x * x))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -4e-266)
		tmp = Float64(-Float64(Float64(y * y) * Float64(y * y)));
	else
		tmp = Float64(Float64(x + y) * Float64(x * Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (((x ^ 4.0) - (y ^ 4.0)) <= -4e-266)
		tmp = -((y * y) * (y * y));
	else
		tmp = (x + y) * (x * (x * x));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision], -4e-266], (-N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]), N[(N[(x + y), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\
\;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\

\mathbf{else}:\\
\;\;\;\;\left(x + y\right) \cdot \left(x \cdot \left(x \cdot x\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < -3.9999999999999999e-266

    1. Initial program 100.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
      2. lift-pow.f64N/A

        \[\leadsto {x}^{4} - \color{blue}{{y}^{4}} \]
      3. flip--N/A

        \[\leadsto \color{blue}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      5. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      6. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}}}} \]
      7. flip--N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      8. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      9. lower-/.f6499.9

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{{x}^{4} - {y}^{4}}}} \]
      10. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      11. lift-pow.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4}} - {y}^{4}}} \]
      12. sqr-powN/A

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

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{4}}}} \]
      14. sqr-powN/A

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}}}} \]
      15. difference-of-squaresN/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
      16. lower-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{{y}^{2}} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    6. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
      2. lower-*.f6498.9

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    7. Applied rewrites98.9%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

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

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

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right)}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      6. unpow1N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{\left(\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\right)}^{1}}}} \]
      7. pow-flipN/A

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

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

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      10. remove-double-div98.9

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      11. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      12. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
      13. lower-*.f6498.9

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    9. Applied rewrites98.9%

      \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    10. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\left(-1 \cdot {y}^{2}\right)} \cdot \left(y \cdot y\right) \]
    11. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \left(-1 \cdot \color{blue}{\left(y \cdot y\right)}\right) \cdot \left(y \cdot y\right) \]
      2. associate-*r*N/A

        \[\leadsto \color{blue}{\left(\left(-1 \cdot y\right) \cdot y\right)} \cdot \left(y \cdot y\right) \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      5. mul-1-negN/A

        \[\leadsto \left(y \cdot \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot \left(y \cdot y\right) \]
      6. lower-neg.f6499.1

        \[\leadsto \left(y \cdot \color{blue}{\left(-y\right)}\right) \cdot \left(y \cdot y\right) \]
    12. Applied rewrites99.1%

      \[\leadsto \color{blue}{\left(y \cdot \left(-y\right)\right)} \cdot \left(y \cdot y\right) \]

    if -3.9999999999999999e-266 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

    1. Initial program 78.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. sqr-powN/A

        \[\leadsto \color{blue}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)}} - {y}^{4} \]
      2. sqr-powN/A

        \[\leadsto {x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}} \]
      3. difference-of-squaresN/A

        \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)} \]
      5. metadata-evalN/A

        \[\leadsto \left({x}^{\color{blue}{2}} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      6. unpow2N/A

        \[\leadsto \left(\color{blue}{x \cdot x} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      7. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, {y}^{\left(\frac{4}{2}\right)}\right)} \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, {y}^{\color{blue}{2}}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      9. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      10. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, \color{blue}{y \cdot y}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      11. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left({x}^{\color{blue}{2}} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      12. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{x \cdot x} - {y}^{\left(\frac{4}{2}\right)}\right) \]
      13. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - {y}^{\color{blue}{2}}\right) \]
      14. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x \cdot x - \color{blue}{y \cdot y}\right) \]
      15. difference-of-squaresN/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      16. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      17. lower-+.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
      18. lower--.f6499.9

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
    4. Applied rewrites99.9%

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

        \[\leadsto \left(x \cdot x + \color{blue}{y \cdot y}\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
      2. lift-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
      3. lift-+.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
      4. lift--.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right) \]
      5. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      6. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)} \]
      7. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)} \cdot \mathsf{fma}\left(x, x, y \cdot y\right) \]
      8. associate-*l*N/A

        \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
      9. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
      10. lower-*.f6499.9

        \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
    6. Applied rewrites99.9%

      \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
    7. Taylor expanded in x around inf

      \[\leadsto \left(x + y\right) \cdot \color{blue}{{x}^{3}} \]
    8. Step-by-step derivation
      1. cube-multN/A

        \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \]
      2. unpow2N/A

        \[\leadsto \left(x + y\right) \cdot \left(x \cdot \color{blue}{{x}^{2}}\right) \]
      3. lower-*.f64N/A

        \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(x \cdot {x}^{2}\right)} \]
      4. unpow2N/A

        \[\leadsto \left(x + y\right) \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      5. lower-*.f6496.6

        \[\leadsto \left(x + y\right) \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
    9. Applied rewrites96.6%

      \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + y\right) \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 91.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (- (pow x 4.0) (pow y 4.0)) -4e-266)
   (- (* (* y y) (* y y)))
   (* x (* x (* x x)))))
double code(double x, double y) {
	double tmp;
	if ((pow(x, 4.0) - pow(y, 4.0)) <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else {
		tmp = x * (x * (x * x));
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: tmp
    if (((x ** 4.0d0) - (y ** 4.0d0)) <= (-4d-266)) then
        tmp = -((y * y) * (y * y))
    else
        tmp = x * (x * (x * x))
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((Math.pow(x, 4.0) - Math.pow(y, 4.0)) <= -4e-266) {
		tmp = -((y * y) * (y * y));
	} else {
		tmp = x * (x * (x * x));
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -4e-266:
		tmp = -((y * y) * (y * y))
	else:
		tmp = x * (x * (x * x))
	return tmp
function code(x, y)
	tmp = 0.0
	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -4e-266)
		tmp = Float64(-Float64(Float64(y * y) * Float64(y * y)));
	else
		tmp = Float64(x * Float64(x * Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (((x ^ 4.0) - (y ^ 4.0)) <= -4e-266)
		tmp = -((y * y) * (y * y));
	else
		tmp = x * (x * (x * x));
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[LessEqual[N[(N[Power[x, 4.0], $MachinePrecision] - N[Power[y, 4.0], $MachinePrecision]), $MachinePrecision], -4e-266], (-N[(N[(y * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]), N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\
\;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64))) < -3.9999999999999999e-266

    1. Initial program 100.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-pow.f64N/A

        \[\leadsto \color{blue}{{x}^{4}} - {y}^{4} \]
      2. lift-pow.f64N/A

        \[\leadsto {x}^{4} - \color{blue}{{y}^{4}} \]
      3. flip--N/A

        \[\leadsto \color{blue}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      5. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\frac{{x}^{4} + {y}^{4}}{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}}} \]
      6. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{x}^{4} \cdot {x}^{4} - {y}^{4} \cdot {y}^{4}}{{x}^{4} + {y}^{4}}}}} \]
      7. flip--N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      8. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      9. lower-/.f6499.9

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{{x}^{4} - {y}^{4}}}} \]
      10. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4} - {y}^{4}}}} \]
      11. lift-pow.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{x}^{4}} - {y}^{4}}} \]
      12. sqr-powN/A

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

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{4}}}} \]
      14. sqr-powN/A

        \[\leadsto \frac{1}{\frac{1}{{x}^{\left(\frac{4}{2}\right)} \cdot {x}^{\left(\frac{4}{2}\right)} - \color{blue}{{y}^{\left(\frac{4}{2}\right)} \cdot {y}^{\left(\frac{4}{2}\right)}}}} \]
      15. difference-of-squaresN/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
      16. lower-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left({x}^{\left(\frac{4}{2}\right)} + {y}^{\left(\frac{4}{2}\right)}\right) \cdot \left({x}^{\left(\frac{4}{2}\right)} - {y}^{\left(\frac{4}{2}\right)}\right)}}} \]
    4. Applied rewrites99.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{{y}^{2}} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    6. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
      2. lower-*.f6498.9

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    7. Applied rewrites98.9%

      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

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

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

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \color{blue}{\left(x - y\right)}\right)}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\left(y \cdot y\right) \cdot \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      6. unpow1N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{{\left(\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\right)}^{1}}}} \]
      7. pow-flipN/A

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

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

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)}}} \]
      10. remove-double-div98.9

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      11. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      12. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
      13. lower-*.f6498.9

        \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    9. Applied rewrites98.9%

      \[\leadsto \color{blue}{\left(\left(x + y\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)} \]
    10. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\left(-1 \cdot {y}^{2}\right)} \cdot \left(y \cdot y\right) \]
    11. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \left(-1 \cdot \color{blue}{\left(y \cdot y\right)}\right) \cdot \left(y \cdot y\right) \]
      2. associate-*r*N/A

        \[\leadsto \color{blue}{\left(\left(-1 \cdot y\right) \cdot y\right)} \cdot \left(y \cdot y\right) \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(y \cdot \left(-1 \cdot y\right)\right)} \cdot \left(y \cdot y\right) \]
      5. mul-1-negN/A

        \[\leadsto \left(y \cdot \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot \left(y \cdot y\right) \]
      6. lower-neg.f6499.1

        \[\leadsto \left(y \cdot \color{blue}{\left(-y\right)}\right) \cdot \left(y \cdot y\right) \]
    12. Applied rewrites99.1%

      \[\leadsto \color{blue}{\left(y \cdot \left(-y\right)\right)} \cdot \left(y \cdot y\right) \]

    if -3.9999999999999999e-266 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

    1. Initial program 78.0%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{{x}^{4}} \]
    4. Step-by-step derivation
      1. lower-pow.f6491.1

        \[\leadsto \color{blue}{{x}^{4}} \]
    5. Applied rewrites91.1%

      \[\leadsto \color{blue}{{x}^{4}} \]
    6. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto {x}^{\color{blue}{\left(3 + 1\right)}} \]
      2. pow-plusN/A

        \[\leadsto \color{blue}{{x}^{3} \cdot x} \]
      3. cube-unmultN/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
      4. lift-*.f64N/A

        \[\leadsto \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot x \]
      5. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
      6. lower-*.f6491.0

        \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]
    7. Applied rewrites91.0%

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -4 \cdot 10^{-266}:\\ \;\;\;\;-\left(y \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 56.8% accurate, 12.9× speedup?

\[\begin{array}{l} \\ x \cdot \left(x \cdot \left(x \cdot x\right)\right) \end{array} \]
(FPCore (x y) :precision binary64 (* x (* x (* x x))))
double code(double x, double y) {
	return x * (x * (x * x));
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x * (x * (x * x))
end function
public static double code(double x, double y) {
	return x * (x * (x * x));
}
def code(x, y):
	return x * (x * (x * x))
function code(x, y)
	return Float64(x * Float64(x * Float64(x * x)))
end
function tmp = code(x, y)
	tmp = x * (x * (x * x));
end
code[x_, y_] := N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(x \cdot \left(x \cdot x\right)\right)
\end{array}
Derivation
  1. Initial program 85.5%

    \[{x}^{4} - {y}^{4} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{{x}^{4}} \]
  4. Step-by-step derivation
    1. lower-pow.f6460.4

      \[\leadsto \color{blue}{{x}^{4}} \]
  5. Applied rewrites60.4%

    \[\leadsto \color{blue}{{x}^{4}} \]
  6. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto {x}^{\color{blue}{\left(3 + 1\right)}} \]
    2. pow-plusN/A

      \[\leadsto \color{blue}{{x}^{3} \cdot x} \]
    3. cube-unmultN/A

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
    4. lift-*.f64N/A

      \[\leadsto \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot x \]
    5. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x \]
    6. lower-*.f6460.3

      \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]
  7. Applied rewrites60.3%

    \[\leadsto \color{blue}{\left(x \cdot \left(x \cdot x\right)\right) \cdot x} \]
  8. Final simplification60.3%

    \[\leadsto x \cdot \left(x \cdot \left(x \cdot x\right)\right) \]
  9. Add Preprocessing

Alternative 6: 56.7% accurate, 12.9× speedup?

\[\begin{array}{l} \\ \left(x \cdot x\right) \cdot \left(x \cdot x\right) \end{array} \]
(FPCore (x y) :precision binary64 (* (* x x) (* x x)))
double code(double x, double y) {
	return (x * x) * (x * x);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x * x) * (x * x)
end function
public static double code(double x, double y) {
	return (x * x) * (x * x);
}
def code(x, y):
	return (x * x) * (x * x)
function code(x, y)
	return Float64(Float64(x * x) * Float64(x * x))
end
function tmp = code(x, y)
	tmp = (x * x) * (x * x);
end
code[x_, y_] := N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot x\right) \cdot \left(x \cdot x\right)
\end{array}
Derivation
  1. Initial program 85.5%

    \[{x}^{4} - {y}^{4} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf

    \[\leadsto \color{blue}{{x}^{4}} \]
  4. Step-by-step derivation
    1. lower-pow.f6460.4

      \[\leadsto \color{blue}{{x}^{4}} \]
  5. Applied rewrites60.4%

    \[\leadsto \color{blue}{{x}^{4}} \]
  6. Step-by-step derivation
    1. metadata-evalN/A

      \[\leadsto {x}^{\color{blue}{\left(2 + 2\right)}} \]
    2. pow-prod-upN/A

      \[\leadsto \color{blue}{{x}^{2} \cdot {x}^{2}} \]
    3. pow-prod-downN/A

      \[\leadsto \color{blue}{{\left(x \cdot x\right)}^{2}} \]
    4. lift-*.f64N/A

      \[\leadsto {\color{blue}{\left(x \cdot x\right)}}^{2} \]
    5. pow2N/A

      \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
    6. lower-*.f6460.3

      \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
  7. Applied rewrites60.3%

    \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)} \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2024216 
(FPCore (x y)
  :name "Radioactive exchange between two surfaces"
  :precision binary64
  (- (pow x 4.0) (pow y 4.0)))