fabs fraction 1

Percentage Accurate: 92.1% → 99.9%
Time: 7.2s
Alternatives: 10
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 10 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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
          18. 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?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;z \leq -6.2 \cdot 10^{+62}:\\ \;\;\;\;\left|\frac{z}{y\_m} \cdot x\right|\\ \mathbf{elif}\;z \leq 1.05 \cdot 10^{+47}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y\_m} \cdot z\right|\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (if (<= z -6.2e+62)
         (fabs (* (/ z y_m) x))
         (if (<= z 1.05e+47) (fabs (/ (- x -4.0) y_m)) (fabs (* (/ x y_m) z)))))
      y_m = fabs(y);
      double code(double x, double y_m, double z) {
      	double tmp;
      	if (z <= -6.2e+62) {
      		tmp = fabs(((z / y_m) * x));
      	} else if (z <= 1.05e+47) {
      		tmp = fabs(((x - -4.0) / y_m));
      	} else {
      		tmp = fabs(((x / y_m) * z));
      	}
      	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) :: tmp
          if (z <= (-6.2d+62)) then
              tmp = abs(((z / y_m) * x))
          else if (z <= 1.05d+47) then
              tmp = abs(((x - (-4.0d0)) / y_m))
          else
              tmp = abs(((x / y_m) * z))
          end if
          code = tmp
      end function
      
      y_m = Math.abs(y);
      public static double code(double x, double y_m, double z) {
      	double tmp;
      	if (z <= -6.2e+62) {
      		tmp = Math.abs(((z / y_m) * x));
      	} else if (z <= 1.05e+47) {
      		tmp = Math.abs(((x - -4.0) / y_m));
      	} else {
      		tmp = Math.abs(((x / y_m) * z));
      	}
      	return tmp;
      }
      
      y_m = math.fabs(y)
      def code(x, y_m, z):
      	tmp = 0
      	if z <= -6.2e+62:
      		tmp = math.fabs(((z / y_m) * x))
      	elif z <= 1.05e+47:
      		tmp = math.fabs(((x - -4.0) / y_m))
      	else:
      		tmp = math.fabs(((x / y_m) * z))
      	return tmp
      
      y_m = abs(y)
      function code(x, y_m, z)
      	tmp = 0.0
      	if (z <= -6.2e+62)
      		tmp = abs(Float64(Float64(z / y_m) * x));
      	elseif (z <= 1.05e+47)
      		tmp = abs(Float64(Float64(x - -4.0) / y_m));
      	else
      		tmp = abs(Float64(Float64(x / y_m) * z));
      	end
      	return tmp
      end
      
      y_m = abs(y);
      function tmp_2 = code(x, y_m, z)
      	tmp = 0.0;
      	if (z <= -6.2e+62)
      		tmp = abs(((z / y_m) * x));
      	elseif (z <= 1.05e+47)
      		tmp = abs(((x - -4.0) / y_m));
      	else
      		tmp = abs(((x / y_m) * z));
      	end
      	tmp_2 = tmp;
      end
      
      y_m = N[Abs[y], $MachinePrecision]
      code[x_, y$95$m_, z_] := If[LessEqual[z, -6.2e+62], N[Abs[N[(N[(z / y$95$m), $MachinePrecision] * x), $MachinePrecision]], $MachinePrecision], If[LessEqual[z, 1.05e+47], N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(x / y$95$m), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision]]]
      
      \begin{array}{l}
      y_m = \left|y\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;z \leq -6.2 \cdot 10^{+62}:\\
      \;\;\;\;\left|\frac{z}{y\_m} \cdot x\right|\\
      
      \mathbf{elif}\;z \leq 1.05 \cdot 10^{+47}:\\
      \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\
      
      \mathbf{else}:\\
      \;\;\;\;\left|\frac{x}{y\_m} \cdot z\right|\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if z < -6.20000000000000029e62

        1. Initial program 91.8%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 rewrites90.0%

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

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

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

            \[\leadsto \left|\color{blue}{\frac{z}{y} \cdot x}\right| \]
          4. lower-/.f6475.6

            \[\leadsto \left|\color{blue}{\frac{z}{y}} \cdot x\right| \]
        7. Applied rewrites75.6%

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

        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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        if 1.05e47 < z

        1. Initial program 77.2%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 rewrites89.4%

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

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

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

            \[\leadsto \left|\color{blue}{\frac{z}{y} \cdot x}\right| \]
          4. lower-/.f6478.4

            \[\leadsto \left|\color{blue}{\frac{z}{y}} \cdot x\right| \]
        7. Applied rewrites78.4%

          \[\leadsto \left|\color{blue}{\frac{z}{y} \cdot x}\right| \]
        8. Step-by-step derivation
          1. Applied rewrites81.4%

            \[\leadsto \color{blue}{\left|\frac{x}{y} \cdot z\right|} \]
        9. Recombined 3 regimes into one program.
        10. Add Preprocessing

        Alternative 6: 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

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

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

              \[\leadsto \left|\color{blue}{\frac{z}{y} \cdot x}\right| \]
            4. lower-/.f6477.0

              \[\leadsto \left|\color{blue}{\frac{z}{y}} \cdot x\right| \]
          7. Applied rewrites77.0%

            \[\leadsto \left|\color{blue}{\frac{z}{y} \cdot x}\right| \]
          8. Step-by-step derivation
            1. Applied rewrites77.3%

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

            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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

          Alternative 7: 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 8: 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 9: 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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
              18. 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 10: 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))))