Radioactive exchange between two surfaces

Percentage Accurate: 85.3% → 99.9%
Time: 4.8s
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: 85.3% 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?

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

\\
\left(y + x\right) \cdot \left(\mathsf{fma}\left(x, x, y \cdot y\right) \cdot \left(x - y\right)\right)
\end{array}
Derivation
  1. Initial program 87.1%

    \[{x}^{4} - {y}^{4} \]
  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. Applied rewrites52.9%

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

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

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

Alternative 2: 92.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {x}^{4} - {y}^{4}\\ t_1 := \left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{if}\;t\_0 \leq -5 \cdot 10^{-311}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq \infty:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(x \cdot x\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (pow x 4.0) (pow y 4.0))) (t_1 (* (* (- y) y) (* y y))))
   (if (<= t_0 -5e-311) 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 * y) * (y * y);
	double tmp;
	if (t_0 <= -5e-311) {
		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 * y) * (y * y);
	double tmp;
	if (t_0 <= -5e-311) {
		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 * y) * (y * y)
	tmp = 0
	if t_0 <= -5e-311:
		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) * y) * Float64(y * y))
	tmp = 0.0
	if (t_0 <= -5e-311)
		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 * y) * (y * y);
	tmp = 0.0;
	if (t_0 <= -5e-311)
		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[((-y) * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -5e-311], 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\right) \cdot y\right) \cdot \left(y \cdot y\right)\\
\mathbf{if}\;t\_0 \leq -5 \cdot 10^{-311}:\\
\;\;\;\;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))) < -5.00000000000023e-311 or +inf.0 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

    1. Initial program 70.5%

      \[{x}^{4} - {y}^{4} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

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

        \[\leadsto \color{blue}{-{y}^{4}} \]
      3. lower-pow.f6490.2

        \[\leadsto -\color{blue}{{y}^{4}} \]
    5. Applied rewrites90.2%

      \[\leadsto \color{blue}{-{y}^{4}} \]
    6. Step-by-step derivation
      1. Applied rewrites90.0%

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

      if -5.00000000000023e-311 < (-.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--.f6499.8

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

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

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

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

          \[\leadsto 1 \cdot {x}^{4} + \color{blue}{0} \cdot {x}^{4} \]
        5. distribute-rgt-inN/A

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

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

          \[\leadsto \color{blue}{{x}^{4}} \]
        8. 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 rewrites99.8%

          \[\leadsto \left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      9. Recombined 2 regimes into one program.
      10. Add Preprocessing

      Alternative 3: 99.6% accurate, 0.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot y\right) \cdot y\right) \cdot \left(y + x\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= (- (pow x 4.0) (pow y 4.0)) -5e-311)
         (* (* (* (- x y) y) y) (+ y x))
         (* (* (* (- x y) x) x) (+ y x))))
      double code(double x, double y) {
      	double tmp;
      	if ((pow(x, 4.0) - pow(y, 4.0)) <= -5e-311) {
      		tmp = (((x - y) * y) * y) * (y + x);
      	} else {
      		tmp = (((x - y) * x) * x) * (y + 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-311)) then
              tmp = (((x - y) * y) * y) * (y + x)
          else
              tmp = (((x - y) * x) * x) * (y + 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-311) {
      		tmp = (((x - y) * y) * y) * (y + x);
      	} else {
      		tmp = (((x - y) * x) * x) * (y + x);
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -5e-311:
      		tmp = (((x - y) * y) * y) * (y + x)
      	else:
      		tmp = (((x - y) * x) * x) * (y + x)
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -5e-311)
      		tmp = Float64(Float64(Float64(Float64(x - y) * y) * y) * Float64(y + x));
      	else
      		tmp = Float64(Float64(Float64(Float64(x - y) * x) * x) * Float64(y + x));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y)
      	tmp = 0.0;
      	if (((x ^ 4.0) - (y ^ 4.0)) <= -5e-311)
      		tmp = (((x - y) * y) * y) * (y + x);
      	else
      		tmp = (((x - y) * x) * x) * (y + 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-311], N[(N[(N[(N[(x - y), $MachinePrecision] * y), $MachinePrecision] * y), $MachinePrecision] * N[(y + x), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(x - y), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * N[(y + x), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\
      \;\;\;\;\left(\left(\left(x - y\right) \cdot y\right) \cdot y\right) \cdot \left(y + x\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\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))) < -5.00000000000023e-311

        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. Applied rewrites94.9%

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

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

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

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

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

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

            \[\leadsto \left(x \cdot {y}^{2} + \color{blue}{\left(-1 \cdot y\right) \cdot {y}^{2}}\right) \cdot \left(x + y\right) \]
          5. distribute-rgt-inN/A

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

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

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

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

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

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

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

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

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

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

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

        if -5.00000000000023e-311 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

        1. Initial program 81.4%

          \[{x}^{4} - {y}^{4} \]
        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. Applied rewrites34.1%

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

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

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

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

            \[\leadsto \left(\color{blue}{{x}^{2} \cdot \left(\mathsf{neg}\left(y\right)\right)} + {x}^{3}\right) \cdot \left(x + y\right) \]
          3. mul-1-negN/A

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \left(\left(\left(x + \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot x\right) \cdot x\right) \cdot \left(x + y\right) \]
          15. unsub-negN/A

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

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

          \[\leadsto \color{blue}{\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right)} \cdot \left(x + y\right) \]
      3. Recombined 2 regimes into one program.
      4. Final simplification99.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot y\right) \cdot y\right) \cdot \left(y + x\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 4: 99.6% accurate, 0.9× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\ \;\;\;\;\left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= (- (pow x 4.0) (pow y 4.0)) -5e-311)
         (* (* (- y) y) (* y y))
         (* (* (* (- x y) x) x) (+ y x))))
      double code(double x, double y) {
      	double tmp;
      	if ((pow(x, 4.0) - pow(y, 4.0)) <= -5e-311) {
      		tmp = (-y * y) * (y * y);
      	} else {
      		tmp = (((x - y) * x) * x) * (y + 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-311)) then
              tmp = (-y * y) * (y * y)
          else
              tmp = (((x - y) * x) * x) * (y + 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-311) {
      		tmp = (-y * y) * (y * y);
      	} else {
      		tmp = (((x - y) * x) * x) * (y + x);
      	}
      	return tmp;
      }
      
      def code(x, y):
      	tmp = 0
      	if (math.pow(x, 4.0) - math.pow(y, 4.0)) <= -5e-311:
      		tmp = (-y * y) * (y * y)
      	else:
      		tmp = (((x - y) * x) * x) * (y + x)
      	return tmp
      
      function code(x, y)
      	tmp = 0.0
      	if (Float64((x ^ 4.0) - (y ^ 4.0)) <= -5e-311)
      		tmp = Float64(Float64(Float64(-y) * y) * Float64(y * y));
      	else
      		tmp = Float64(Float64(Float64(Float64(x - y) * x) * x) * Float64(y + x));
      	end
      	return tmp
      end
      
      function tmp_2 = code(x, y)
      	tmp = 0.0;
      	if (((x ^ 4.0) - (y ^ 4.0)) <= -5e-311)
      		tmp = (-y * y) * (y * y);
      	else
      		tmp = (((x - y) * x) * x) * (y + 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-311], N[(N[((-y) * y), $MachinePrecision] * N[(y * y), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(x - y), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * N[(y + x), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\
      \;\;\;\;\left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\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))) < -5.00000000000023e-311

        1. Initial program 100.0%

          \[{x}^{4} - {y}^{4} \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{-1 \cdot {y}^{4}} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

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

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

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

          \[\leadsto \color{blue}{-{y}^{4}} \]
        6. Step-by-step derivation
          1. Applied rewrites99.7%

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

          if -5.00000000000023e-311 < (-.f64 (pow.f64 x #s(literal 4 binary64)) (pow.f64 y #s(literal 4 binary64)))

          1. Initial program 81.4%

            \[{x}^{4} - {y}^{4} \]
          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. Applied rewrites34.1%

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

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

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

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

              \[\leadsto \left(\color{blue}{{x}^{2} \cdot \left(\mathsf{neg}\left(y\right)\right)} + {x}^{3}\right) \cdot \left(x + y\right) \]
            3. mul-1-negN/A

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left(\left(\left(x + \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot x\right) \cdot x\right) \cdot \left(x + y\right) \]
            15. unsub-negN/A

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

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

            \[\leadsto \color{blue}{\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right)} \cdot \left(x + y\right) \]
        7. Recombined 2 regimes into one program.
        8. Final simplification99.8%

          \[\leadsto \begin{array}{l} \mathbf{if}\;{x}^{4} - {y}^{4} \leq -5 \cdot 10^{-311}:\\ \;\;\;\;\left(\left(-y\right) \cdot y\right) \cdot \left(y \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(x - y\right) \cdot x\right) \cdot x\right) \cdot \left(y + x\right)\\ \end{array} \]
        9. Add Preprocessing

        Alternative 5: 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 87.1%

          \[{x}^{4} - {y}^{4} \]
        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. distribute-rgt-inN/A

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

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

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

            \[\leadsto 1 \cdot {x}^{4} + \color{blue}{0} \cdot {x}^{4} \]
          5. distribute-rgt-inN/A

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

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

            \[\leadsto \color{blue}{{x}^{4}} \]
          8. lower-pow.f6461.3

            \[\leadsto \color{blue}{{x}^{4}} \]
        7. Applied rewrites61.3%

          \[\leadsto \color{blue}{{x}^{4}} \]
        8. Step-by-step derivation
          1. Applied rewrites61.2%

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

          Reproduce

          ?
          herbie shell --seed 2024312 
          (FPCore (x y)
            :name "Radioactive exchange between two surfaces"
            :precision binary64
            (- (pow x 4.0) (pow y 4.0)))