Radioactive exchange between two surfaces

Percentage Accurate: 85.4% → 99.9%
Time: 5.4s
Alternatives: 5
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 5 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: 85.4% 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?

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

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

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

      \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
    2. sub-negN/A

      \[\leadsto \color{blue}{{x}^{4} + \left(\mathsf{neg}\left({y}^{4}\right)\right)} \]
    3. +-commutativeN/A

      \[\leadsto \color{blue}{\left(\mathsf{neg}\left({y}^{4}\right)\right) + {x}^{4}} \]
    4. lift-pow.f64N/A

      \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{y}^{4}}\right)\right) + {x}^{4} \]
    5. sqr-powN/A

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

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

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

      \[\leadsto \left(\mathsf{neg}\left({y}^{\left(\frac{4}{2}\right)}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + {x}^{4} \]
    9. associate-*r*N/A

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

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

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

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

      \[\leadsto \mathsf{fma}\left(\left(\mathsf{neg}\left(\color{blue}{y \cdot y}\right)\right) \cdot y, y, {x}^{4}\right) \]
    14. distribute-lft-neg-inN/A

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

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) \cdot y\right)} \cdot y, y, {x}^{4}\right) \]
    16. lower-neg.f6486.6

      \[\leadsto \mathsf{fma}\left(\left(\color{blue}{\left(-y\right)} \cdot y\right) \cdot y, y, {x}^{4}\right) \]
  4. Applied rewrites86.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {x}^{4}\right)} \]
  5. Step-by-step derivation
    1. lift-pow.f64N/A

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

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

      \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{{\left({x}^{2}\right)}^{2}}\right) \]
    4. pow2N/A

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

      \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {\color{blue}{\left(x \cdot x\right)}}^{2}\right) \]
    6. pow2N/A

      \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
    7. lower-*.f6486.6

      \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
  6. Applied rewrites86.6%

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

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

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

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

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

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

      \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot y\right) \cdot \left(y \cdot y\right) \]
    7. distribute-lft-neg-outN/A

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

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

      \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\mathsf{neg}\left(y \cdot y\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
    10. cancel-sign-sub-invN/A

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

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

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

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

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

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

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

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

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

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

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

    \[\leadsto \color{blue}{\left(x - y\right) \cdot \left(\left(x + y\right) \cdot \mathsf{fma}\left(y, y, x \cdot x\right)\right)} \]
  9. Final simplification99.9%

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

Alternative 2: 99.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ t_1 := \left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-322}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (pow x 4.0) (pow y 4.0)))
        (t_1 (* (* (+ y x) (- x y)) (* y y))))
   (if (<= t_0 -5e-322) t_1 (if (<= t_0 INFINITY) (* (* x x) (* x x)) t_1))))
double code(double x, double y) {
	double t_0 = pow(x, 4.0) - pow(y, 4.0);
	double t_1 = ((y + x) * (x - y)) * (y * y);
	double tmp;
	if (t_0 <= -5e-322) {
		tmp = t_1;
	} else if (t_0 <= ((double) INFINITY)) {
		tmp = (x * x) * (x * x);
	} else {
		tmp = t_1;
	}
	return tmp;
}
public static double code(double x, double y) {
	double t_0 = Math.pow(x, 4.0) - Math.pow(y, 4.0);
	double t_1 = ((y + x) * (x - y)) * (y * y);
	double tmp;
	if (t_0 <= -5e-322) {
		tmp = t_1;
	} else if (t_0 <= Double.POSITIVE_INFINITY) {
		tmp = (x * x) * (x * x);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y):
	t_0 = math.pow(x, 4.0) - math.pow(y, 4.0)
	t_1 = ((y + x) * (x - y)) * (y * y)
	tmp = 0
	if t_0 <= -5e-322:
		tmp = t_1
	elif t_0 <= math.inf:
		tmp = (x * x) * (x * x)
	else:
		tmp = t_1
	return tmp
function code(x, y)
	t_0 = Float64((x ^ 4.0) - (y ^ 4.0))
	t_1 = Float64(Float64(Float64(y + x) * Float64(x - y)) * Float64(y * y))
	tmp = 0.0
	if (t_0 <= -5e-322)
		tmp = t_1;
	elseif (t_0 <= Inf)
		tmp = Float64(Float64(x * x) * Float64(x * x));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (x ^ 4.0) - (y ^ 4.0);
	t_1 = ((y + x) * (x - y)) * (y * y);
	tmp = 0.0;
	if (t_0 <= -5e-322)
		tmp = t_1;
	elseif (t_0 <= Inf)
		tmp = (x * x) * (x * x);
	else
		tmp = t_1;
	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]}, Block[{t$95$1 = N[(N[(N[(y + x), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -5e-322], t$95$1, If[LessEqual[t$95$0, Infinity], N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision], t$95$1]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {x}^{4} - {y}^{4}\\
t_1 := \left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\
\mathbf{if}\;t\_0 \leq -5 \cdot 10^{-322}:\\
\;\;\;\;t\_1\\

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

\mathbf{else}:\\
\;\;\;\;t\_1\\


\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))) < -4.99006e-322 or +inf.0 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

    1. Initial program 74.8%

      \[{x}^{4} - {y}^{4} \]
    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. +-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    if -4.99006e-322 < (-.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. 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. +-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{4} \cdot \left(1 + \left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right)\right)} \]
    6. Step-by-step derivation
      1. associate-+r+N/A

        \[\leadsto {x}^{4} \cdot \color{blue}{\left(\left(1 + -1 \cdot \frac{y}{x}\right) + \frac{y}{x}\right)} \]
      2. associate-+r+N/A

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

        \[\leadsto {x}^{4} \cdot \color{blue}{\left(\left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right) + 1\right)} \]
      4. distribute-lft1-inN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{\left(-1 + 1\right) \cdot \frac{y}{x}} + 1\right) \]
      5. metadata-evalN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{0} \cdot \frac{y}{x} + 1\right) \]
      6. mul0-lftN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{0} + 1\right) \]
      7. metadata-evalN/A

        \[\leadsto {x}^{4} \cdot \color{blue}{1} \]
      8. *-rgt-identityN/A

        \[\leadsto \color{blue}{{x}^{4}} \]
      9. lower-pow.f64100.0

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

      \[\leadsto \color{blue}{{x}^{4}} \]
    8. Step-by-step derivation
      1. Applied rewrites99.9%

        \[\leadsto \left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
    9. Recombined 2 regimes into one program.
    10. Final simplification99.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\ \;\;\;\;\left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\ \mathbf{elif}\;{x}^{4} - {y}^{4} \leq \infty:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\ \end{array} \]
    11. Add Preprocessing

    Alternative 3: 99.7% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot y\right) \cdot y\right) \cdot \left(x - y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\right)\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (if (<= (- (pow x 4.0) (pow y 4.0)) -5e-322)
       (* (* (* (+ y x) y) y) (- x y))
       (* (* (* (+ y x) x) x) (- x y))))
    double code(double x, double y) {
    	double tmp;
    	if ((pow(x, 4.0) - pow(y, 4.0)) <= -5e-322) {
    		tmp = (((y + x) * y) * y) * (x - y);
    	} else {
    		tmp = (((y + x) * x) * x) * (x - y);
    	}
    	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-322)) then
            tmp = (((y + x) * y) * y) * (x - y)
        else
            tmp = (((y + x) * x) * x) * (x - y)
        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-322) {
    		tmp = (((y + x) * y) * y) * (x - y);
    	} else {
    		tmp = (((y + x) * x) * x) * (x - y);
    	}
    	return tmp;
    }
    
    def code(x, y):
    	tmp = 0
    	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -5e-322:
    		tmp = (((y + x) * y) * y) * (x - y)
    	else:
    		tmp = (((y + x) * x) * x) * (x - y)
    	return tmp
    
    function code(x, y)
    	tmp = 0.0
    	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -5e-322)
    		tmp = Float64(Float64(Float64(Float64(y + x) * y) * y) * Float64(x - y));
    	else
    		tmp = Float64(Float64(Float64(Float64(y + x) * x) * x) * Float64(x - y));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	tmp = 0.0;
    	if (((x ^ 4.0) - (y ^ 4.0)) <= -5e-322)
    		tmp = (((y + x) * y) * y) * (x - y);
    	else
    		tmp = (((y + x) * x) * x) * (x - y);
    	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-322], N[(N[(N[(N[(y + x), $MachinePrecision] * y), $MachinePrecision] * y), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(y + x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\
    \;\;\;\;\left(\left(\left(y + x\right) \cdot y\right) \cdot y\right) \cdot \left(x - y\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\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))) < -4.99006e-322

      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. sub-negN/A

          \[\leadsto \color{blue}{{x}^{4} + \left(\mathsf{neg}\left({y}^{4}\right)\right)} \]
        3. +-commutativeN/A

          \[\leadsto \color{blue}{\left(\mathsf{neg}\left({y}^{4}\right)\right) + {x}^{4}} \]
        4. lift-pow.f64N/A

          \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{y}^{4}}\right)\right) + {x}^{4} \]
        5. sqr-powN/A

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

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

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

          \[\leadsto \left(\mathsf{neg}\left({y}^{\left(\frac{4}{2}\right)}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + {x}^{4} \]
        9. associate-*r*N/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\left(\mathsf{neg}\left(\color{blue}{y \cdot y}\right)\right) \cdot y, y, {x}^{4}\right) \]
        14. distribute-lft-neg-inN/A

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) \cdot y\right)} \cdot y, y, {x}^{4}\right) \]
        16. lower-neg.f6499.8

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {x}^{4}\right)} \]
      5. Step-by-step derivation
        1. lift-pow.f64N/A

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

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{{\left({x}^{2}\right)}^{2}}\right) \]
        4. pow2N/A

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {\color{blue}{\left(x \cdot x\right)}}^{2}\right) \]
        6. pow2N/A

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

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

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

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

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

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

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot y\right) \cdot \left(y \cdot y\right) \]
        7. distribute-lft-neg-outN/A

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\mathsf{neg}\left(y \cdot y\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
        10. cancel-sign-sub-invN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(x - y\right) \cdot \color{blue}{\left(x \cdot {y}^{2} + {y}^{3}\right)} \]
      10. Step-by-step derivation
        1. cube-multN/A

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

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

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

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

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

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

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

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

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

          \[\leadsto \left(x - y\right) \cdot \left(\left(\color{blue}{\left(y + x\right)} \cdot y\right) \cdot y\right) \]
        11. lower-+.f6499.1

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

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

      if -4.99006e-322 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

      1. Initial program 74.7%

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

          \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
        2. sub-negN/A

          \[\leadsto \color{blue}{{x}^{4} + \left(\mathsf{neg}\left({y}^{4}\right)\right)} \]
        3. +-commutativeN/A

          \[\leadsto \color{blue}{\left(\mathsf{neg}\left({y}^{4}\right)\right) + {x}^{4}} \]
        4. lift-pow.f64N/A

          \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{y}^{4}}\right)\right) + {x}^{4} \]
        5. sqr-powN/A

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

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

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

          \[\leadsto \left(\mathsf{neg}\left({y}^{\left(\frac{4}{2}\right)}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + {x}^{4} \]
        9. associate-*r*N/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\left(\mathsf{neg}\left(\color{blue}{y \cdot y}\right)\right) \cdot y, y, {x}^{4}\right) \]
        14. distribute-lft-neg-inN/A

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) \cdot y\right)} \cdot y, y, {x}^{4}\right) \]
        16. lower-neg.f6476.7

          \[\leadsto \mathsf{fma}\left(\left(\color{blue}{\left(-y\right)} \cdot y\right) \cdot y, y, {x}^{4}\right) \]
      4. Applied rewrites76.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {x}^{4}\right)} \]
      5. Step-by-step derivation
        1. lift-pow.f64N/A

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

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{{\left({x}^{2}\right)}^{2}}\right) \]
        4. pow2N/A

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {\color{blue}{\left(x \cdot x\right)}}^{2}\right) \]
        6. pow2N/A

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
        7. lower-*.f6476.7

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
      6. Applied rewrites76.7%

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

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

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

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

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot y\right) \cdot \left(y \cdot y\right) \]
        7. distribute-lft-neg-outN/A

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\mathsf{neg}\left(y \cdot y\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
        10. cancel-sign-sub-invN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(x - y\right) \cdot \color{blue}{\left({x}^{2} \cdot y + {x}^{3}\right)} \]
      10. Step-by-step derivation
        1. unpow3N/A

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

          \[\leadsto \left(x - y\right) \cdot \left({x}^{2} \cdot y + \color{blue}{{x}^{2}} \cdot x\right) \]
        3. distribute-lft-outN/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(x - y\right) \cdot \color{blue}{\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot y\right) \cdot y\right) \cdot \left(x - y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 99.6% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\ \;\;\;\;\left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\right)\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (if (<= (- (pow x 4.0) (pow y 4.0)) -5e-322)
       (* (* (+ y x) (- x y)) (* y y))
       (* (* (* (+ y x) x) x) (- x y))))
    double code(double x, double y) {
    	double tmp;
    	if ((pow(x, 4.0) - pow(y, 4.0)) <= -5e-322) {
    		tmp = ((y + x) * (x - y)) * (y * y);
    	} else {
    		tmp = (((y + x) * x) * x) * (x - y);
    	}
    	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-322)) then
            tmp = ((y + x) * (x - y)) * (y * y)
        else
            tmp = (((y + x) * x) * x) * (x - y)
        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-322) {
    		tmp = ((y + x) * (x - y)) * (y * y);
    	} else {
    		tmp = (((y + x) * x) * x) * (x - y);
    	}
    	return tmp;
    }
    
    def code(x, y):
    	tmp = 0
    	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -5e-322:
    		tmp = ((y + x) * (x - y)) * (y * y)
    	else:
    		tmp = (((y + x) * x) * x) * (x - y)
    	return tmp
    
    function code(x, y)
    	tmp = 0.0
    	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -5e-322)
    		tmp = Float64(Float64(Float64(y + x) * Float64(x - y)) * Float64(y * y));
    	else
    		tmp = Float64(Float64(Float64(Float64(y + x) * x) * x) * Float64(x - y));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	tmp = 0.0;
    	if (((x ^ 4.0) - (y ^ 4.0)) <= -5e-322)
    		tmp = ((y + x) * (x - y)) * (y * y);
    	else
    		tmp = (((y + x) * x) * x) * (x - y);
    	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-322], N[(N[(N[(y + x), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(y + x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * N[(x - y), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\
    \;\;\;\;\left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\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))) < -4.99006e-322

      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. +-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, y, x \cdot x\right) \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right)} \]
      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-*.f6499.0

          \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot \left(\left(x + y\right) \cdot \left(x - y\right)\right) \]
      7. Applied rewrites99.0%

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

      if -4.99006e-322 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

      1. Initial program 74.7%

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

          \[\leadsto \color{blue}{{x}^{4} - {y}^{4}} \]
        2. sub-negN/A

          \[\leadsto \color{blue}{{x}^{4} + \left(\mathsf{neg}\left({y}^{4}\right)\right)} \]
        3. +-commutativeN/A

          \[\leadsto \color{blue}{\left(\mathsf{neg}\left({y}^{4}\right)\right) + {x}^{4}} \]
        4. lift-pow.f64N/A

          \[\leadsto \left(\mathsf{neg}\left(\color{blue}{{y}^{4}}\right)\right) + {x}^{4} \]
        5. sqr-powN/A

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

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

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

          \[\leadsto \left(\mathsf{neg}\left({y}^{\left(\frac{4}{2}\right)}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + {x}^{4} \]
        9. associate-*r*N/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\left(\mathsf{neg}\left(\color{blue}{y \cdot y}\right)\right) \cdot y, y, {x}^{4}\right) \]
        14. distribute-lft-neg-inN/A

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) \cdot y\right)} \cdot y, y, {x}^{4}\right) \]
        16. lower-neg.f6476.7

          \[\leadsto \mathsf{fma}\left(\left(\color{blue}{\left(-y\right)} \cdot y\right) \cdot y, y, {x}^{4}\right) \]
      4. Applied rewrites76.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {x}^{4}\right)} \]
      5. Step-by-step derivation
        1. lift-pow.f64N/A

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

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{{\left({x}^{2}\right)}^{2}}\right) \]
        4. pow2N/A

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

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, {\color{blue}{\left(x \cdot x\right)}}^{2}\right) \]
        6. pow2N/A

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
        7. lower-*.f6476.7

          \[\leadsto \mathsf{fma}\left(\left(\left(-y\right) \cdot y\right) \cdot y, y, \color{blue}{\left(x \cdot x\right) \cdot \left(x \cdot x\right)}\right) \]
      6. Applied rewrites76.7%

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

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

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

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

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot y\right) \cdot \left(y \cdot y\right) \]
        7. distribute-lft-neg-outN/A

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

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

          \[\leadsto \left(x \cdot x\right) \cdot \left(x \cdot x\right) + \left(\mathsf{neg}\left(y \cdot y\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} \]
        10. cancel-sign-sub-invN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(x - y\right) \cdot \color{blue}{\left({x}^{2} \cdot y + {x}^{3}\right)} \]
      10. Step-by-step derivation
        1. unpow3N/A

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

          \[\leadsto \left(x - y\right) \cdot \left({x}^{2} \cdot y + \color{blue}{{x}^{2}} \cdot x\right) \]
        3. distribute-lft-outN/A

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(x - y\right) \cdot \color{blue}{\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification99.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-322}:\\ \;\;\;\;\left(\left(y + x\right) \cdot \left(x - y\right)\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(y + x\right) \cdot x\right) \cdot x\right) \cdot \left(x - y\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 5: 57.5% 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. 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. +-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{{x}^{4} \cdot \left(1 + \left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right)\right)} \]
    6. Step-by-step derivation
      1. associate-+r+N/A

        \[\leadsto {x}^{4} \cdot \color{blue}{\left(\left(1 + -1 \cdot \frac{y}{x}\right) + \frac{y}{x}\right)} \]
      2. associate-+r+N/A

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

        \[\leadsto {x}^{4} \cdot \color{blue}{\left(\left(-1 \cdot \frac{y}{x} + \frac{y}{x}\right) + 1\right)} \]
      4. distribute-lft1-inN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{\left(-1 + 1\right) \cdot \frac{y}{x}} + 1\right) \]
      5. metadata-evalN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{0} \cdot \frac{y}{x} + 1\right) \]
      6. mul0-lftN/A

        \[\leadsto {x}^{4} \cdot \left(\color{blue}{0} + 1\right) \]
      7. metadata-evalN/A

        \[\leadsto {x}^{4} \cdot \color{blue}{1} \]
      8. *-rgt-identityN/A

        \[\leadsto \color{blue}{{x}^{4}} \]
      9. lower-pow.f6453.1

        \[\leadsto \color{blue}{{x}^{4}} \]
    7. Applied rewrites53.1%

      \[\leadsto \color{blue}{{x}^{4}} \]
    8. Step-by-step derivation
      1. Applied rewrites53.1%

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

      Reproduce

      ?
      herbie shell --seed 2024304 
      (FPCore (x y)
        :name "Radioactive exchange between two surfaces"
        :precision binary64
        (- (pow x 4.0) (pow y 4.0)))