Radioactive exchange between two surfaces

Percentage Accurate: 85.9% → 99.8%
Time: 7.7s
Alternatives: 8
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 8 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: 99.8% accurate, 4.6× speedup?

\[\begin{array}{l} \\ \left(x + y\right) \cdot \frac{x - y}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right)}} \end{array} \]
(FPCore (x y)
 :precision binary64
 (* (+ x y) (/ (- x y) (/ 1.0 (fma x x (* y y))))))
double code(double x, double y) {
	return (x + y) * ((x - y) / (1.0 / fma(x, x, (y * y))));
}
function code(x, y)
	return Float64(Float64(x + y) * Float64(Float64(x - y) / Float64(1.0 / fma(x, x, Float64(y * y)))))
end
code[x_, y_] := N[(N[(x + y), $MachinePrecision] * N[(N[(x - y), $MachinePrecision] / N[(1.0 / N[(x * x + N[(y * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x + y\right) \cdot \frac{x - y}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right)}}
\end{array}
Derivation
  1. Initial program 84.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
    21. 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

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

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

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

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

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

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

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

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \left(\color{blue}{x \cdot x} + y \cdot y\right)\right) \]
    4. flip-+N/A

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\frac{\left(x \cdot x\right) \cdot \left(x \cdot x\right) - \left(y \cdot y\right) \cdot \left(y \cdot y\right)}{x \cdot x - y \cdot y}}\right) \]
    5. pow2N/A

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

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \frac{{\color{blue}{\left(x \cdot x\right)}}^{2} - \left(y \cdot y\right) \cdot \left(y \cdot y\right)}{x \cdot x - y \cdot y}\right) \]
    7. pow2N/A

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

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

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \frac{{x}^{\color{blue}{4}} - \left(y \cdot y\right) \cdot \left(y \cdot y\right)}{x \cdot x - y \cdot y}\right) \]
    10. pow2N/A

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

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \frac{{x}^{4} - {\color{blue}{\left(y \cdot y\right)}}^{2}}{x \cdot x - y \cdot y}\right) \]
    12. pow2N/A

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

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

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

      \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\frac{1}{\frac{x \cdot x - y \cdot y}{{x}^{4} - {y}^{4}}}}\right) \]
    16. un-div-invN/A

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

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

      \[\leadsto \left(x + y\right) \cdot \frac{x - y}{\color{blue}{\frac{1}{\frac{{x}^{4} - {y}^{4}}{x \cdot x - y \cdot y}}}} \]
  8. Applied rewrites99.9%

    \[\leadsto \left(x + y\right) \cdot \color{blue}{\frac{x - y}{\frac{1}{\mathsf{fma}\left(x, x, y \cdot y\right)}}} \]
  9. Add Preprocessing

Alternative 2: 99.4% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \left(y \cdot y\right)\right)\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (pow x 4.0) (pow y 4.0))))
   (if (<= t_0 -5e-286)
     (* (+ x y) (* (- x 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 <= -5e-286) {
		tmp = (x + y) * ((x - 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 <= -5e-286) {
		tmp = (x + y) * ((x - 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 <= -5e-286:
		tmp = (x + y) * ((x - 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 <= -5e-286)
		tmp = Float64(Float64(x + y) * Float64(Float64(x - 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 <= -5e-286)
		tmp = (x + y) * ((x - 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, -5e-286], N[(N[(x + y), $MachinePrecision] * N[(N[(x - y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $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 -5 \cdot 10^{-286}:\\
\;\;\;\;\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \left(y \cdot y\right)\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))) < -5.00000000000000037e-286

    1. Initial program 100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
      21. lower--.f6499.6

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

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

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

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

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

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

        \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
      6. lower-*.f6499.7

        \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
    6. Applied rewrites99.7%

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

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

        \[\leadsto \left(x + y\right) \cdot \left(\left(x - y\right) \cdot \color{blue}{\left(y \cdot y\right)}\right) \]
      2. lower-*.f6499.7

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

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

    if -5.00000000000000037e-286 < (-.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. Applied rewrites99.9%

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

      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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
        21. 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%

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
    7. Recombined 3 regimes into one program.
    8. Final simplification99.9%

      \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \left(y \cdot y\right)\right)\\ \mathbf{elif}\;{x}^{4} - {y}^{4} \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \]
    9. Add Preprocessing

    Alternative 3: 99.4% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (let* ((t_0 (- (pow x 4.0) (pow y 4.0))))
       (if (<= t_0 -5e-286)
         (* (* 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 <= -5e-286) {
    		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 <= -5e-286) {
    		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 <= -5e-286:
    		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 <= -5e-286)
    		tmp = Float64(Float64(y * y) * Float64(y * Float64(-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 <= -5e-286)
    		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, -5e-286], 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 -5 \cdot 10^{-286}:\\
    \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\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))) < -5.00000000000000037e-286

      1. Initial program 100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
        21. lower--.f6499.6

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      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-*.f6499.6

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

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

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

          \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
        2. lower-neg.f64N/A

          \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
        3. unpow2N/A

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

          \[\leadsto \left(y \cdot y\right) \cdot \left(-\color{blue}{y \cdot y}\right) \]
      10. Applied rewrites99.6%

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

      if -5.00000000000000037e-286 < (-.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. Applied rewrites99.9%

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

        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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
          21. 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%

          \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
      7. Recombined 3 regimes into one program.
      8. Final simplification99.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{elif}\;{x}^{4} - {y}^{4} \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)\\ \end{array} \]
      9. Add Preprocessing

      Alternative 4: 96.0% accurate, 0.5× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + y\right) \cdot \left(-y \cdot \left(y \cdot y\right)\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (let* ((t_0 (- (pow x 4.0) (pow y 4.0))))
         (if (<= t_0 -5e-286)
           (* (* y y) (* y (- y)))
           (if (<= t_0 INFINITY)
             (* x (* x (* x x)))
             (* (+ x y) (- (* y (* y y))))))))
      double code(double x, double y) {
      	double t_0 = pow(x, 4.0) - pow(y, 4.0);
      	double tmp;
      	if (t_0 <= -5e-286) {
      		tmp = (y * y) * (y * -y);
      	} else if (t_0 <= ((double) INFINITY)) {
      		tmp = x * (x * (x * x));
      	} else {
      		tmp = (x + y) * -(y * (y * 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 <= -5e-286) {
      		tmp = (y * y) * (y * -y);
      	} else if (t_0 <= Double.POSITIVE_INFINITY) {
      		tmp = x * (x * (x * x));
      	} else {
      		tmp = (x + y) * -(y * (y * y));
      	}
      	return tmp;
      }
      
      def code(x, y):
      	t_0 = math.pow(x, 4.0) - math.pow(y, 4.0)
      	tmp = 0
      	if t_0 <= -5e-286:
      		tmp = (y * y) * (y * -y)
      	elif t_0 <= math.inf:
      		tmp = x * (x * (x * x))
      	else:
      		tmp = (x + y) * -(y * (y * y))
      	return tmp
      
      function code(x, y)
      	t_0 = Float64((x ^ 4.0) - (y ^ 4.0))
      	tmp = 0.0
      	if (t_0 <= -5e-286)
      		tmp = Float64(Float64(y * y) * Float64(y * Float64(-y)));
      	elseif (t_0 <= Inf)
      		tmp = Float64(x * Float64(x * Float64(x * x)));
      	else
      		tmp = Float64(Float64(x + y) * Float64(-Float64(y * Float64(y * 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 <= -5e-286)
      		tmp = (y * y) * (y * -y);
      	elseif (t_0 <= Inf)
      		tmp = x * (x * (x * x));
      	else
      		tmp = (x + y) * -(y * (y * 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, -5e-286], 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[(x + y), $MachinePrecision] * (-N[(y * N[(y * y), $MachinePrecision]), $MachinePrecision])), $MachinePrecision]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := {x}^{4} - {y}^{4}\\
      \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-286}:\\
      \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\
      
      \mathbf{elif}\;t\_0 \leq \infty:\\
      \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(x + y\right) \cdot \left(-y \cdot \left(y \cdot 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))) < -5.00000000000000037e-286

        1. Initial program 100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
          21. lower--.f6499.6

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

          \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
        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-*.f6499.6

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

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

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

            \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
          2. lower-neg.f64N/A

            \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
          3. unpow2N/A

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

            \[\leadsto \left(y \cdot y\right) \cdot \left(-\color{blue}{y \cdot y}\right) \]
        10. Applied rewrites99.6%

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

        if -5.00000000000000037e-286 < (-.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. Applied rewrites99.9%

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

          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. lift--.f64N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{3}\right)\right)} \]
            2. unpow3N/A

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

              \[\leadsto \left(x + y\right) \cdot \left(\mathsf{neg}\left(\color{blue}{{y}^{2}} \cdot y\right)\right) \]
            4. distribute-rgt-neg-inN/A

              \[\leadsto \left(x + y\right) \cdot \color{blue}{\left({y}^{2} \cdot \left(\mathsf{neg}\left(y\right)\right)\right)} \]
            5. mul-1-negN/A

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

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

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

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

              \[\leadsto \left(x + y\right) \cdot \left(\left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \]
            10. lower-neg.f6471.8

              \[\leadsto \left(x + y\right) \cdot \left(\left(y \cdot y\right) \cdot \color{blue}{\left(-y\right)}\right) \]
          9. Applied rewrites71.8%

            \[\leadsto \left(x + y\right) \cdot \color{blue}{\left(\left(y \cdot y\right) \cdot \left(-y\right)\right)} \]
        7. Recombined 3 regimes into one program.
        8. Final simplification95.5%

          \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{elif}\;{x}^{4} - {y}^{4} \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x + y\right) \cdot \left(-y \cdot \left(y \cdot y\right)\right)\\ \end{array} \]
        9. Add Preprocessing

        Alternative 5: 92.3% accurate, 0.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (if (<= (- (pow x 4.0) (pow y 4.0)) -5e-286)
           (* (* 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)) <= -5e-286) {
        		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)) <= (-5d-286)) 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)) <= -5e-286) {
        		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)) <= -5e-286:
        		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)) <= -5e-286)
        		tmp = Float64(Float64(y * y) * Float64(y * Float64(-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)) <= -5e-286)
        		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], -5e-286], 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 -5 \cdot 10^{-286}:\\
        \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\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))) < -5.00000000000000037e-286

          1. Initial program 100.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
            21. lower--.f6499.6

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
          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-*.f6499.6

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

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

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

              \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
            2. lower-neg.f64N/A

              \[\leadsto \left(y \cdot y\right) \cdot \color{blue}{\left(\mathsf{neg}\left({y}^{2}\right)\right)} \]
            3. unpow2N/A

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

              \[\leadsto \left(y \cdot y\right) \cdot \left(-\color{blue}{y \cdot y}\right) \]
          10. Applied rewrites99.6%

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

          if -5.00000000000000037e-286 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

          1. Initial program 76.9%

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

            \[\leadsto \color{blue}{{x}^{4}} \]
          4. Step-by-step derivation
            1. lower-pow.f6487.6

              \[\leadsto \color{blue}{{x}^{4}} \]
          5. Applied rewrites87.6%

            \[\leadsto \color{blue}{{x}^{4}} \]
          6. Step-by-step derivation
            1. Applied rewrites87.5%

              \[\leadsto \left(x \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{x} \]
          7. Recombined 2 regimes into one program.
          8. Final simplification91.6%

            \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-286}:\\ \;\;\;\;\left(y \cdot y\right) \cdot \left(y \cdot \left(-y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\ \end{array} \]
          9. Add Preprocessing

          Alternative 6: 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 84.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(\color{blue}{\left(x + y\right)} \cdot \left(x - y\right)\right) \]
            21. 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

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

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

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

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

              \[\leadsto \color{blue}{\left(x + y\right) \cdot \left(\left(x - y\right) \cdot \mathsf{fma}\left(x, x, y \cdot y\right)\right)} \]
            6. 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 7: 57.9% 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 84.8%

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

            \[\leadsto \color{blue}{{x}^{4}} \]
          4. Step-by-step derivation
            1. lower-pow.f6458.5

              \[\leadsto \color{blue}{{x}^{4}} \]
          5. Applied rewrites58.5%

            \[\leadsto \color{blue}{{x}^{4}} \]
          6. Step-by-step derivation
            1. Applied rewrites58.4%

              \[\leadsto \left(x \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{x} \]
            2. Final simplification58.4%

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

            Alternative 8: 57.9% 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 84.8%

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

              \[\leadsto \color{blue}{{x}^{4}} \]
            4. Step-by-step derivation
              1. lower-pow.f6458.5

                \[\leadsto \color{blue}{{x}^{4}} \]
            5. Applied rewrites58.5%

              \[\leadsto \color{blue}{{x}^{4}} \]
            6. Step-by-step derivation
              1. Applied rewrites58.4%

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

              Reproduce

              ?
              herbie shell --seed 2024226 
              (FPCore (x y)
                :name "Radioactive exchange between two surfaces"
                :precision binary64
                (- (pow x 4.0) (pow y 4.0)))