fabs fraction 1

Percentage Accurate: 92.1% → 99.9%
Time: 7.5s
Alternatives: 9
Speedup: 1.2×

Specification

?
\[\begin{array}{l} \\ \left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \end{array} \]
(FPCore (x y z) :precision binary64 (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))
double code(double x, double y, double z) {
	return fabs((((x + 4.0) / y) - ((x / y) * z)));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = abs((((x + 4.0d0) / y) - ((x / y) * z)))
end function
public static double code(double x, double y, double z) {
	return Math.abs((((x + 4.0) / y) - ((x / y) * z)));
}
def code(x, y, z):
	return math.fabs((((x + 4.0) / y) - ((x / y) * z)))
function code(x, y, z)
	return abs(Float64(Float64(Float64(x + 4.0) / y) - Float64(Float64(x / y) * z)))
end
function tmp = code(x, y, z)
	tmp = abs((((x + 4.0) / y) - ((x / y) * z)));
end
code[x_, y_, z_] := N[Abs[N[(N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision] - N[(N[(x / y), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|
\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 9 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: 92.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \end{array} \]
(FPCore (x y z) :precision binary64 (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))
double code(double x, double y, double z) {
	return fabs((((x + 4.0) / y) - ((x / y) * z)));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = abs((((x + 4.0d0) / y) - ((x / y) * z)))
end function
public static double code(double x, double y, double z) {
	return Math.abs((((x + 4.0) / y) - ((x / y) * z)));
}
def code(x, y, z):
	return math.fabs((((x + 4.0) / y) - ((x / y) * z)))
function code(x, y, z)
	return abs(Float64(Float64(Float64(x + 4.0) / y) - Float64(Float64(x / y) * z)))
end
function tmp = code(x, y, z)
	tmp = abs((((x + 4.0) / y) - ((x / y) * z)));
end
code[x_, y_, z_] := N[Abs[N[(N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision] - N[(N[(x / y), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|
\end{array}

Alternative 1: 99.9% accurate, 0.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 20000000:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\mathsf{fma}\left(-x, \frac{z}{y\_m}, \frac{4 + x}{y\_m}\right)\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (if (<= y_m 20000000.0)
   (fabs (/ (fma z x (- -4.0 x)) y_m))
   (fabs (fma (- x) (/ z y_m) (/ (+ 4.0 x) y_m)))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double tmp;
	if (y_m <= 20000000.0) {
		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
	} else {
		tmp = fabs(fma(-x, (z / y_m), ((4.0 + x) / y_m)));
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	tmp = 0.0
	if (y_m <= 20000000.0)
		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
	else
		tmp = abs(fma(Float64(-x), Float64(z / y_m), Float64(Float64(4.0 + x) / y_m)));
	end
	return tmp
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := If[LessEqual[y$95$m, 20000000.0], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], N[Abs[N[((-x) * N[(z / y$95$m), $MachinePrecision] + N[(N[(4.0 + x), $MachinePrecision] / y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 20000000:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\mathsf{fma}\left(-x, \frac{z}{y\_m}, \frac{4 + x}{y\_m}\right)\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 2e7

    1. Initial program 88.4%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
      2. neg-fabsN/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      3. lower-fabs.f64N/A

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

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
      5. sub-negN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
      6. +-commutativeN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
      7. distribute-neg-inN/A

        \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
      8. remove-double-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
      9. sub-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
      10. lift-*.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
      11. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
      12. associate-*l/N/A

        \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
      13. lift-/.f64N/A

        \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
      14. sub-divN/A

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

        \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
    4. Applied rewrites97.8%

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]

    if 2e7 < y

    1. Initial program 98.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y} - \frac{x}{y} \cdot z}\right| \]
      2. sub-negN/A

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

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

        \[\leadsto \left|\left(\mathsf{neg}\left(\color{blue}{\frac{x}{y} \cdot z}\right)\right) + \frac{x + 4}{y}\right| \]
      5. lift-/.f64N/A

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

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

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

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

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

        \[\leadsto \left|\mathsf{fma}\left(\color{blue}{-x}, \frac{z}{y}, \frac{x + 4}{y}\right)\right| \]
      11. lower-/.f6499.8

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

        \[\leadsto \left|\mathsf{fma}\left(-x, \frac{z}{y}, \frac{\color{blue}{x + 4}}{y}\right)\right| \]
      13. +-commutativeN/A

        \[\leadsto \left|\mathsf{fma}\left(-x, \frac{z}{y}, \frac{\color{blue}{4 + x}}{y}\right)\right| \]
      14. lower-+.f6499.8

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

      \[\leadsto \left|\color{blue}{\mathsf{fma}\left(-x, \frac{z}{y}, \frac{4 + x}{y}\right)}\right| \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 98.2% accurate, 0.5× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \frac{4 + x}{y\_m}\\ t_1 := \frac{x}{y\_m} \cdot z\\ \mathbf{if}\;t\_0 - t\_1 \leq -2 \cdot 10^{-56}:\\ \;\;\;\;\left|t\_1 - t\_0\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (/ (+ 4.0 x) y_m)) (t_1 (* (/ x y_m) z)))
   (if (<= (- t_0 t_1) -2e-56)
     (fabs (- t_1 t_0))
     (fabs (/ (fma z x (- -4.0 x)) y_m)))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double t_0 = (4.0 + x) / y_m;
	double t_1 = (x / y_m) * z;
	double tmp;
	if ((t_0 - t_1) <= -2e-56) {
		tmp = fabs((t_1 - t_0));
	} else {
		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	t_0 = Float64(Float64(4.0 + x) / y_m)
	t_1 = Float64(Float64(x / y_m) * z)
	tmp = 0.0
	if (Float64(t_0 - t_1) <= -2e-56)
		tmp = abs(Float64(t_1 - t_0));
	else
		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
	end
	return tmp
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := Block[{t$95$0 = N[(N[(4.0 + x), $MachinePrecision] / y$95$m), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x / y$95$m), $MachinePrecision] * z), $MachinePrecision]}, If[LessEqual[N[(t$95$0 - t$95$1), $MachinePrecision], -2e-56], N[Abs[N[(t$95$1 - t$95$0), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
t_0 := \frac{4 + x}{y\_m}\\
t_1 := \frac{x}{y\_m} \cdot z\\
\mathbf{if}\;t\_0 - t\_1 \leq -2 \cdot 10^{-56}:\\
\;\;\;\;\left|t\_1 - t\_0\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 (+.f64 x #s(literal 4 binary64)) y) (*.f64 (/.f64 x y) z)) < -2.0000000000000001e-56

    1. Initial program 99.9%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing

    if -2.0000000000000001e-56 < (-.f64 (/.f64 (+.f64 x #s(literal 4 binary64)) y) (*.f64 (/.f64 x y) z))

    1. Initial program 86.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
      2. neg-fabsN/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      3. lower-fabs.f64N/A

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

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
      5. sub-negN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
      6. +-commutativeN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
      7. distribute-neg-inN/A

        \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
      8. remove-double-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
      9. sub-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
      10. lift-*.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
      11. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
      12. associate-*l/N/A

        \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
      13. lift-/.f64N/A

        \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
      14. sub-divN/A

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

        \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
    4. Applied rewrites96.5%

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{4 + x}{y} - \frac{x}{y} \cdot z \leq -2 \cdot 10^{-56}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z - \frac{4 + x}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.0% accurate, 1.1× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -48:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 0.041:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (fabs (* (- 1.0 z) (/ x y_m)))))
   (if (<= x -48.0) t_0 (if (<= x 0.041) (fabs (/ (fma z x -4.0) y_m)) t_0))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double t_0 = fabs(((1.0 - z) * (x / y_m)));
	double tmp;
	if (x <= -48.0) {
		tmp = t_0;
	} else if (x <= 0.041) {
		tmp = fabs((fma(z, x, -4.0) / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	t_0 = abs(Float64(Float64(1.0 - z) * Float64(x / y_m)))
	tmp = 0.0
	if (x <= -48.0)
		tmp = t_0;
	elseif (x <= 0.041)
		tmp = abs(Float64(fma(z, x, -4.0) / y_m));
	else
		tmp = t_0;
	end
	return tmp
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[(N[(1.0 - z), $MachinePrecision] * N[(x / y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -48.0], t$95$0, If[LessEqual[x, 0.041], N[Abs[N[(N[(z * x + -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\
\mathbf{if}\;x \leq -48:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 0.041:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -48 or 0.0410000000000000017 < x

    1. Initial program 88.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \left|\color{blue}{x \cdot \left(\frac{1}{y} - \frac{z}{y}\right)}\right| \]
    4. Step-by-step derivation
      1. distribute-lft-out--N/A

        \[\leadsto \left|\color{blue}{x \cdot \frac{1}{y} - x \cdot \frac{z}{y}}\right| \]
      2. associate-*r/N/A

        \[\leadsto \left|\color{blue}{\frac{x \cdot 1}{y}} - x \cdot \frac{z}{y}\right| \]
      3. *-rgt-identityN/A

        \[\leadsto \left|\frac{\color{blue}{x}}{y} - x \cdot \frac{z}{y}\right| \]
      4. associate-/l*N/A

        \[\leadsto \left|\frac{x}{y} - \color{blue}{\frac{x \cdot z}{y}}\right| \]
      5. *-commutativeN/A

        \[\leadsto \left|\frac{x}{y} - \frac{\color{blue}{z \cdot x}}{y}\right| \]
      6. associate-/l*N/A

        \[\leadsto \left|\frac{x}{y} - \color{blue}{z \cdot \frac{x}{y}}\right| \]
      7. cancel-sign-sub-invN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} + \left(\mathsf{neg}\left(z\right)\right) \cdot \frac{x}{y}}\right| \]
      8. mul-1-negN/A

        \[\leadsto \left|\frac{x}{y} + \color{blue}{\left(-1 \cdot z\right)} \cdot \frac{x}{y}\right| \]
      9. distribute-rgt1-inN/A

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

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

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

        \[\leadsto \left|\left(1 + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}\right) \cdot \frac{x}{y}\right| \]
      13. sub-negN/A

        \[\leadsto \left|\color{blue}{\left(1 - z\right)} \cdot \frac{x}{y}\right| \]
      14. lower--.f64N/A

        \[\leadsto \left|\color{blue}{\left(1 - z\right)} \cdot \frac{x}{y}\right| \]
      15. lower-/.f6498.8

        \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
    5. Applied rewrites98.8%

      \[\leadsto \left|\color{blue}{\left(1 - z\right) \cdot \frac{x}{y}}\right| \]

    if -48 < x < 0.0410000000000000017

    1. Initial program 94.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
      2. neg-fabsN/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      3. lower-fabs.f64N/A

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

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
      5. sub-negN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
      6. +-commutativeN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
      7. distribute-neg-inN/A

        \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
      8. remove-double-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
      9. sub-negN/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
      10. lift-*.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
      11. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
      12. associate-*l/N/A

        \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
      13. lift-/.f64N/A

        \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
      14. sub-divN/A

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

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

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
    5. Taylor expanded in x around 0

      \[\leadsto \left|\frac{\mathsf{fma}\left(z, x, \color{blue}{-4}\right)}{y}\right| \]
    6. Step-by-step derivation
      1. Applied rewrites98.9%

        \[\leadsto \left|\frac{\mathsf{fma}\left(z, x, \color{blue}{-4}\right)}{y}\right| \]
    7. Recombined 2 regimes into one program.
    8. Add Preprocessing

    Alternative 4: 95.6% accurate, 1.1× speedup?

    \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{if}\;z \leq -1:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.7:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    y_m = (fabs.f64 y)
    (FPCore (x y_m z)
     :precision binary64
     (let* ((t_0 (fabs (/ (fma z x -4.0) y_m))))
       (if (<= z -1.0) t_0 (if (<= z 2.7) (fabs (/ (- x -4.0) y_m)) t_0))))
    y_m = fabs(y);
    double code(double x, double y_m, double z) {
    	double t_0 = fabs((fma(z, x, -4.0) / y_m));
    	double tmp;
    	if (z <= -1.0) {
    		tmp = t_0;
    	} else if (z <= 2.7) {
    		tmp = fabs(((x - -4.0) / y_m));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    y_m = abs(y)
    function code(x, y_m, z)
    	t_0 = abs(Float64(fma(z, x, -4.0) / y_m))
    	tmp = 0.0
    	if (z <= -1.0)
    		tmp = t_0;
    	elseif (z <= 2.7)
    		tmp = abs(Float64(Float64(x - -4.0) / y_m));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    y_m = N[Abs[y], $MachinePrecision]
    code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[(N[(z * x + -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -1.0], t$95$0, If[LessEqual[z, 2.7], N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    y_m = \left|y\right|
    
    \\
    \begin{array}{l}
    t_0 := \left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\
    \mathbf{if}\;z \leq -1:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;z \leq 2.7:\\
    \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if z < -1 or 2.7000000000000002 < z

      1. Initial program 87.8%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-fabs.f64N/A

          \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
        2. neg-fabsN/A

          \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
        3. lower-fabs.f64N/A

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

          \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
        5. sub-negN/A

          \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
        6. +-commutativeN/A

          \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
        7. distribute-neg-inN/A

          \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
        8. remove-double-negN/A

          \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
        9. sub-negN/A

          \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
        10. lift-*.f64N/A

          \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
        11. lift-/.f64N/A

          \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
        12. associate-*l/N/A

          \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
        13. lift-/.f64N/A

          \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
        14. sub-divN/A

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

          \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
      4. Applied rewrites91.8%

        \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
      5. Taylor expanded in x around 0

        \[\leadsto \left|\frac{\mathsf{fma}\left(z, x, \color{blue}{-4}\right)}{y}\right| \]
      6. Step-by-step derivation
        1. Applied rewrites90.9%

          \[\leadsto \left|\frac{\mathsf{fma}\left(z, x, \color{blue}{-4}\right)}{y}\right| \]

        if -1 < z < 2.7000000000000002

        1. Initial program 95.6%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Taylor expanded in z around 0

          \[\leadsto \left|\color{blue}{4 \cdot \frac{1}{y} + \frac{x}{y}}\right| \]
        4. Step-by-step derivation
          1. *-rgt-identityN/A

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

            \[\leadsto \left|4 \cdot \frac{1}{y} + \color{blue}{x \cdot \frac{1}{y}}\right| \]
          3. distribute-rgt-outN/A

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

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

            \[\leadsto \left|\frac{\color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot \left(4 + x\right)}{y}\right| \]
          6. distribute-lft-neg-inN/A

            \[\leadsto \left|\frac{\color{blue}{\mathsf{neg}\left(-1 \cdot \left(4 + x\right)\right)}}{y}\right| \]
          7. distribute-frac-negN/A

            \[\leadsto \left|\color{blue}{\mathsf{neg}\left(\frac{-1 \cdot \left(4 + x\right)}{y}\right)}\right| \]
          8. mul-1-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\frac{\color{blue}{\mathsf{neg}\left(\left(4 + x\right)\right)}}{y}\right)\right| \]
          9. distribute-frac-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\frac{4 + x}{y}\right)\right)}\right)\right| \]
          10. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          11. lower-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          12. +-commutativeN/A

            \[\leadsto \left|\frac{\color{blue}{x + 4}}{y}\right| \]
          13. metadata-evalN/A

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

            \[\leadsto \left|\frac{x + \left(\mathsf{neg}\left(\color{blue}{-1 \cdot 4}\right)\right)}{y}\right| \]
          15. sub-negN/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          16. lower--.f64N/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          17. metadata-eval98.4

            \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
        5. Applied rewrites98.4%

          \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
      7. Recombined 2 regimes into one program.
      8. Add Preprocessing

      Alternative 5: 85.3% accurate, 1.2× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{x}{y\_m} \cdot z\right|\\ \mathbf{if}\;z \leq -6.2 \cdot 10^{+62}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 1.05 \cdot 10^{+47}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (let* ((t_0 (fabs (* (/ x y_m) z))))
         (if (<= z -6.2e+62)
           t_0
           (if (<= z 1.05e+47) (fabs (/ (- x -4.0) y_m)) t_0))))
      y_m = fabs(y);
      double code(double x, double y_m, double z) {
      	double t_0 = fabs(((x / y_m) * z));
      	double tmp;
      	if (z <= -6.2e+62) {
      		tmp = t_0;
      	} else if (z <= 1.05e+47) {
      		tmp = fabs(((x - -4.0) / y_m));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      y_m = abs(y)
      real(8) function code(x, y_m, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y_m
          real(8), intent (in) :: z
          real(8) :: t_0
          real(8) :: tmp
          t_0 = abs(((x / y_m) * z))
          if (z <= (-6.2d+62)) then
              tmp = t_0
          else if (z <= 1.05d+47) then
              tmp = abs(((x - (-4.0d0)) / y_m))
          else
              tmp = t_0
          end if
          code = tmp
      end function
      
      y_m = Math.abs(y);
      public static double code(double x, double y_m, double z) {
      	double t_0 = Math.abs(((x / y_m) * z));
      	double tmp;
      	if (z <= -6.2e+62) {
      		tmp = t_0;
      	} else if (z <= 1.05e+47) {
      		tmp = Math.abs(((x - -4.0) / y_m));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      y_m = math.fabs(y)
      def code(x, y_m, z):
      	t_0 = math.fabs(((x / y_m) * z))
      	tmp = 0
      	if z <= -6.2e+62:
      		tmp = t_0
      	elif z <= 1.05e+47:
      		tmp = math.fabs(((x - -4.0) / y_m))
      	else:
      		tmp = t_0
      	return tmp
      
      y_m = abs(y)
      function code(x, y_m, z)
      	t_0 = abs(Float64(Float64(x / y_m) * z))
      	tmp = 0.0
      	if (z <= -6.2e+62)
      		tmp = t_0;
      	elseif (z <= 1.05e+47)
      		tmp = abs(Float64(Float64(x - -4.0) / y_m));
      	else
      		tmp = t_0;
      	end
      	return tmp
      end
      
      y_m = abs(y);
      function tmp_2 = code(x, y_m, z)
      	t_0 = abs(((x / y_m) * z));
      	tmp = 0.0;
      	if (z <= -6.2e+62)
      		tmp = t_0;
      	elseif (z <= 1.05e+47)
      		tmp = abs(((x - -4.0) / y_m));
      	else
      		tmp = t_0;
      	end
      	tmp_2 = tmp;
      end
      
      y_m = N[Abs[y], $MachinePrecision]
      code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[(N[(x / y$95$m), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -6.2e+62], t$95$0, If[LessEqual[z, 1.05e+47], N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
      
      \begin{array}{l}
      y_m = \left|y\right|
      
      \\
      \begin{array}{l}
      t_0 := \left|\frac{x}{y\_m} \cdot z\right|\\
      \mathbf{if}\;z \leq -6.2 \cdot 10^{+62}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;z \leq 1.05 \cdot 10^{+47}:\\
      \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_0\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if z < -6.20000000000000029e62 or 1.05e47 < z

        1. Initial program 84.6%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-fabs.f64N/A

            \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
          2. neg-fabsN/A

            \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
          3. lower-fabs.f64N/A

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

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
          5. sub-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
          6. +-commutativeN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
          7. distribute-neg-inN/A

            \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
          8. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
          9. sub-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
          10. lift-*.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
          11. lift-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
          12. associate-*l/N/A

            \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
          13. lift-/.f64N/A

            \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
          14. sub-divN/A

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

            \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
        4. Applied rewrites89.7%

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
        5. Taylor expanded in z around inf

          \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}}\right| \]
        6. Step-by-step derivation
          1. associate-*l/N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z}\right| \]
          2. lower-*.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z}\right| \]
          3. lower-/.f6477.3

            \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z\right| \]
        7. Applied rewrites77.3%

          \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z}\right| \]

        if -6.20000000000000029e62 < z < 1.05e47

        1. Initial program 96.5%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Taylor expanded in z around 0

          \[\leadsto \left|\color{blue}{4 \cdot \frac{1}{y} + \frac{x}{y}}\right| \]
        4. Step-by-step derivation
          1. *-rgt-identityN/A

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

            \[\leadsto \left|4 \cdot \frac{1}{y} + \color{blue}{x \cdot \frac{1}{y}}\right| \]
          3. distribute-rgt-outN/A

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

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

            \[\leadsto \left|\frac{\color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot \left(4 + x\right)}{y}\right| \]
          6. distribute-lft-neg-inN/A

            \[\leadsto \left|\frac{\color{blue}{\mathsf{neg}\left(-1 \cdot \left(4 + x\right)\right)}}{y}\right| \]
          7. distribute-frac-negN/A

            \[\leadsto \left|\color{blue}{\mathsf{neg}\left(\frac{-1 \cdot \left(4 + x\right)}{y}\right)}\right| \]
          8. mul-1-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\frac{\color{blue}{\mathsf{neg}\left(\left(4 + x\right)\right)}}{y}\right)\right| \]
          9. distribute-frac-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\frac{4 + x}{y}\right)\right)}\right)\right| \]
          10. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          11. lower-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          12. +-commutativeN/A

            \[\leadsto \left|\frac{\color{blue}{x + 4}}{y}\right| \]
          13. metadata-evalN/A

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

            \[\leadsto \left|\frac{x + \left(\mathsf{neg}\left(\color{blue}{-1 \cdot 4}\right)\right)}{y}\right| \]
          15. sub-negN/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          16. lower--.f64N/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          17. metadata-eval92.0

            \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
        5. Applied rewrites92.0%

          \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 6: 97.9% accurate, 1.2× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;x \leq -8.8 \cdot 10^{+55}:\\ \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (if (<= x -8.8e+55)
         (fabs (* (- 1.0 z) (/ x y_m)))
         (fabs (/ (fma z x (- -4.0 x)) y_m))))
      y_m = fabs(y);
      double code(double x, double y_m, double z) {
      	double tmp;
      	if (x <= -8.8e+55) {
      		tmp = fabs(((1.0 - z) * (x / y_m)));
      	} else {
      		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
      	}
      	return tmp;
      }
      
      y_m = abs(y)
      function code(x, y_m, z)
      	tmp = 0.0
      	if (x <= -8.8e+55)
      		tmp = abs(Float64(Float64(1.0 - z) * Float64(x / y_m)));
      	else
      		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
      	end
      	return tmp
      end
      
      y_m = N[Abs[y], $MachinePrecision]
      code[x_, y$95$m_, z_] := If[LessEqual[x, -8.8e+55], N[Abs[N[(N[(1.0 - z), $MachinePrecision] * N[(x / y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]]
      
      \begin{array}{l}
      y_m = \left|y\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq -8.8 \cdot 10^{+55}:\\
      \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\
      
      \mathbf{else}:\\
      \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < -8.80000000000000042e55

        1. Initial program 88.8%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Taylor expanded in x around inf

          \[\leadsto \left|\color{blue}{x \cdot \left(\frac{1}{y} - \frac{z}{y}\right)}\right| \]
        4. Step-by-step derivation
          1. distribute-lft-out--N/A

            \[\leadsto \left|\color{blue}{x \cdot \frac{1}{y} - x \cdot \frac{z}{y}}\right| \]
          2. associate-*r/N/A

            \[\leadsto \left|\color{blue}{\frac{x \cdot 1}{y}} - x \cdot \frac{z}{y}\right| \]
          3. *-rgt-identityN/A

            \[\leadsto \left|\frac{\color{blue}{x}}{y} - x \cdot \frac{z}{y}\right| \]
          4. associate-/l*N/A

            \[\leadsto \left|\frac{x}{y} - \color{blue}{\frac{x \cdot z}{y}}\right| \]
          5. *-commutativeN/A

            \[\leadsto \left|\frac{x}{y} - \frac{\color{blue}{z \cdot x}}{y}\right| \]
          6. associate-/l*N/A

            \[\leadsto \left|\frac{x}{y} - \color{blue}{z \cdot \frac{x}{y}}\right| \]
          7. cancel-sign-sub-invN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} + \left(\mathsf{neg}\left(z\right)\right) \cdot \frac{x}{y}}\right| \]
          8. mul-1-negN/A

            \[\leadsto \left|\frac{x}{y} + \color{blue}{\left(-1 \cdot z\right)} \cdot \frac{x}{y}\right| \]
          9. distribute-rgt1-inN/A

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

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

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

            \[\leadsto \left|\left(1 + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}\right) \cdot \frac{x}{y}\right| \]
          13. sub-negN/A

            \[\leadsto \left|\color{blue}{\left(1 - z\right)} \cdot \frac{x}{y}\right| \]
          14. lower--.f64N/A

            \[\leadsto \left|\color{blue}{\left(1 - z\right)} \cdot \frac{x}{y}\right| \]
          15. lower-/.f64100.0

            \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
        5. Applied rewrites100.0%

          \[\leadsto \left|\color{blue}{\left(1 - z\right) \cdot \frac{x}{y}}\right| \]

        if -8.80000000000000042e55 < x

        1. Initial program 92.1%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-fabs.f64N/A

            \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
          2. neg-fabsN/A

            \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
          3. lower-fabs.f64N/A

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

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
          5. sub-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
          6. +-commutativeN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
          7. distribute-neg-inN/A

            \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
          8. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
          9. sub-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
          10. lift-*.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
          11. lift-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
          12. associate-*l/N/A

            \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
          13. lift-/.f64N/A

            \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
          14. sub-divN/A

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

            \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
        4. Applied rewrites97.9%

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
      3. Recombined 2 regimes into one program.
      4. Add Preprocessing

      Alternative 7: 69.2% accurate, 1.3× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{-x}{y\_m}\right|\\ \mathbf{if}\;x \leq -10.2:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (let* ((t_0 (fabs (/ (- x) y_m))))
         (if (<= x -10.2) t_0 (if (<= x 4.0) (fabs (/ 4.0 y_m)) t_0))))
      y_m = fabs(y);
      double code(double x, double y_m, double z) {
      	double t_0 = fabs((-x / y_m));
      	double tmp;
      	if (x <= -10.2) {
      		tmp = t_0;
      	} else if (x <= 4.0) {
      		tmp = fabs((4.0 / y_m));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      y_m = abs(y)
      real(8) function code(x, y_m, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y_m
          real(8), intent (in) :: z
          real(8) :: t_0
          real(8) :: tmp
          t_0 = abs((-x / y_m))
          if (x <= (-10.2d0)) then
              tmp = t_0
          else if (x <= 4.0d0) then
              tmp = abs((4.0d0 / y_m))
          else
              tmp = t_0
          end if
          code = tmp
      end function
      
      y_m = Math.abs(y);
      public static double code(double x, double y_m, double z) {
      	double t_0 = Math.abs((-x / y_m));
      	double tmp;
      	if (x <= -10.2) {
      		tmp = t_0;
      	} else if (x <= 4.0) {
      		tmp = Math.abs((4.0 / y_m));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      y_m = math.fabs(y)
      def code(x, y_m, z):
      	t_0 = math.fabs((-x / y_m))
      	tmp = 0
      	if x <= -10.2:
      		tmp = t_0
      	elif x <= 4.0:
      		tmp = math.fabs((4.0 / y_m))
      	else:
      		tmp = t_0
      	return tmp
      
      y_m = abs(y)
      function code(x, y_m, z)
      	t_0 = abs(Float64(Float64(-x) / y_m))
      	tmp = 0.0
      	if (x <= -10.2)
      		tmp = t_0;
      	elseif (x <= 4.0)
      		tmp = abs(Float64(4.0 / y_m));
      	else
      		tmp = t_0;
      	end
      	return tmp
      end
      
      y_m = abs(y);
      function tmp_2 = code(x, y_m, z)
      	t_0 = abs((-x / y_m));
      	tmp = 0.0;
      	if (x <= -10.2)
      		tmp = t_0;
      	elseif (x <= 4.0)
      		tmp = abs((4.0 / y_m));
      	else
      		tmp = t_0;
      	end
      	tmp_2 = tmp;
      end
      
      y_m = N[Abs[y], $MachinePrecision]
      code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[((-x) / y$95$m), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -10.2], t$95$0, If[LessEqual[x, 4.0], N[Abs[N[(4.0 / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
      
      \begin{array}{l}
      y_m = \left|y\right|
      
      \\
      \begin{array}{l}
      t_0 := \left|\frac{-x}{y\_m}\right|\\
      \mathbf{if}\;x \leq -10.2:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;x \leq 4:\\
      \;\;\;\;\left|\frac{4}{y\_m}\right|\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_0\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < -10.199999999999999 or 4 < x

        1. Initial program 88.6%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-fabs.f64N/A

            \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
          2. neg-fabsN/A

            \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
          3. lower-fabs.f64N/A

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

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)}\right)\right| \]
          5. sub-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\frac{x + 4}{y} + \left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)}\right)\right| \]
          6. +-commutativeN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right) + \frac{x + 4}{y}\right)}\right)\right| \]
          7. distribute-neg-inN/A

            \[\leadsto \left|\color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right)\right)\right) + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)}\right| \]
          8. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} + \left(\mathsf{neg}\left(\frac{x + 4}{y}\right)\right)\right| \]
          9. sub-negN/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z - \frac{x + 4}{y}}\right| \]
          10. lift-*.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y} \cdot z} - \frac{x + 4}{y}\right| \]
          11. lift-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{x}{y}} \cdot z - \frac{x + 4}{y}\right| \]
          12. associate-*l/N/A

            \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}} - \frac{x + 4}{y}\right| \]
          13. lift-/.f64N/A

            \[\leadsto \left|\frac{x \cdot z}{y} - \color{blue}{\frac{x + 4}{y}}\right| \]
          14. sub-divN/A

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

            \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
        4. Applied rewrites92.0%

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
        5. Taylor expanded in z around 0

          \[\leadsto \left|\frac{\color{blue}{-1 \cdot \left(4 + x\right)}}{y}\right| \]
        6. Step-by-step derivation
          1. distribute-lft-inN/A

            \[\leadsto \left|\frac{\color{blue}{-1 \cdot 4 + -1 \cdot x}}{y}\right| \]
          2. metadata-evalN/A

            \[\leadsto \left|\frac{\color{blue}{-4} + -1 \cdot x}{y}\right| \]
          3. mul-1-negN/A

            \[\leadsto \left|\frac{-4 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}{y}\right| \]
          4. unsub-negN/A

            \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
          5. lower--.f6466.7

            \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
        7. Applied rewrites66.7%

          \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
        8. Taylor expanded in x around inf

          \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
        9. Step-by-step derivation
          1. Applied rewrites66.5%

            \[\leadsto \left|\frac{-x}{y}\right| \]

          if -10.199999999999999 < x < 4

          1. Initial program 94.7%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
          4. Step-by-step derivation
            1. lower-/.f6472.6

              \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
          5. Applied rewrites72.6%

            \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        10. Recombined 2 regimes into one program.
        11. Add Preprocessing

        Alternative 8: 70.1% accurate, 2.1× speedup?

        \[\begin{array}{l} y_m = \left|y\right| \\ \left|\frac{x - -4}{y\_m}\right| \end{array} \]
        y_m = (fabs.f64 y)
        (FPCore (x y_m z) :precision binary64 (fabs (/ (- x -4.0) y_m)))
        y_m = fabs(y);
        double code(double x, double y_m, double z) {
        	return fabs(((x - -4.0) / y_m));
        }
        
        y_m = abs(y)
        real(8) function code(x, y_m, z)
            real(8), intent (in) :: x
            real(8), intent (in) :: y_m
            real(8), intent (in) :: z
            code = abs(((x - (-4.0d0)) / y_m))
        end function
        
        y_m = Math.abs(y);
        public static double code(double x, double y_m, double z) {
        	return Math.abs(((x - -4.0) / y_m));
        }
        
        y_m = math.fabs(y)
        def code(x, y_m, z):
        	return math.fabs(((x - -4.0) / y_m))
        
        y_m = abs(y)
        function code(x, y_m, z)
        	return abs(Float64(Float64(x - -4.0) / y_m))
        end
        
        y_m = abs(y);
        function tmp = code(x, y_m, z)
        	tmp = abs(((x - -4.0) / y_m));
        end
        
        y_m = N[Abs[y], $MachinePrecision]
        code[x_, y$95$m_, z_] := N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]
        
        \begin{array}{l}
        y_m = \left|y\right|
        
        \\
        \left|\frac{x - -4}{y\_m}\right|
        \end{array}
        
        Derivation
        1. Initial program 91.3%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Taylor expanded in z around 0

          \[\leadsto \left|\color{blue}{4 \cdot \frac{1}{y} + \frac{x}{y}}\right| \]
        4. Step-by-step derivation
          1. *-rgt-identityN/A

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

            \[\leadsto \left|4 \cdot \frac{1}{y} + \color{blue}{x \cdot \frac{1}{y}}\right| \]
          3. distribute-rgt-outN/A

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

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

            \[\leadsto \left|\frac{\color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} \cdot \left(4 + x\right)}{y}\right| \]
          6. distribute-lft-neg-inN/A

            \[\leadsto \left|\frac{\color{blue}{\mathsf{neg}\left(-1 \cdot \left(4 + x\right)\right)}}{y}\right| \]
          7. distribute-frac-negN/A

            \[\leadsto \left|\color{blue}{\mathsf{neg}\left(\frac{-1 \cdot \left(4 + x\right)}{y}\right)}\right| \]
          8. mul-1-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\frac{\color{blue}{\mathsf{neg}\left(\left(4 + x\right)\right)}}{y}\right)\right| \]
          9. distribute-frac-negN/A

            \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\frac{4 + x}{y}\right)\right)}\right)\right| \]
          10. remove-double-negN/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          11. lower-/.f64N/A

            \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
          12. +-commutativeN/A

            \[\leadsto \left|\frac{\color{blue}{x + 4}}{y}\right| \]
          13. metadata-evalN/A

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

            \[\leadsto \left|\frac{x + \left(\mathsf{neg}\left(\color{blue}{-1 \cdot 4}\right)\right)}{y}\right| \]
          15. sub-negN/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          16. lower--.f64N/A

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          17. metadata-eval69.8

            \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
        5. Applied rewrites69.8%

          \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
        6. Add Preprocessing

        Alternative 9: 40.7% accurate, 2.6× speedup?

        \[\begin{array}{l} y_m = \left|y\right| \\ \left|\frac{4}{y\_m}\right| \end{array} \]
        y_m = (fabs.f64 y)
        (FPCore (x y_m z) :precision binary64 (fabs (/ 4.0 y_m)))
        y_m = fabs(y);
        double code(double x, double y_m, double z) {
        	return fabs((4.0 / y_m));
        }
        
        y_m = abs(y)
        real(8) function code(x, y_m, z)
            real(8), intent (in) :: x
            real(8), intent (in) :: y_m
            real(8), intent (in) :: z
            code = abs((4.0d0 / y_m))
        end function
        
        y_m = Math.abs(y);
        public static double code(double x, double y_m, double z) {
        	return Math.abs((4.0 / y_m));
        }
        
        y_m = math.fabs(y)
        def code(x, y_m, z):
        	return math.fabs((4.0 / y_m))
        
        y_m = abs(y)
        function code(x, y_m, z)
        	return abs(Float64(4.0 / y_m))
        end
        
        y_m = abs(y);
        function tmp = code(x, y_m, z)
        	tmp = abs((4.0 / y_m));
        end
        
        y_m = N[Abs[y], $MachinePrecision]
        code[x_, y$95$m_, z_] := N[Abs[N[(4.0 / y$95$m), $MachinePrecision]], $MachinePrecision]
        
        \begin{array}{l}
        y_m = \left|y\right|
        
        \\
        \left|\frac{4}{y\_m}\right|
        \end{array}
        
        Derivation
        1. Initial program 91.3%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        4. Step-by-step derivation
          1. lower-/.f6435.4

            \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        5. Applied rewrites35.4%

          \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        6. Add Preprocessing

        Reproduce

        ?
        herbie shell --seed 2024276 
        (FPCore (x y z)
          :name "fabs fraction 1"
          :precision binary64
          (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))