fabs fraction 1

Percentage Accurate: 91.8% → 99.9%
Time: 7.2s
Alternatives: 11
Speedup: 1.1×

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 11 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: 91.8% 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?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -9.8 \cdot 10^{+14}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 3.4 \cdot 10^{+16}:\\ \;\;\;\;\left|\mathsf{fma}\left(x, z, -4\right) - x\right| \cdot \frac{1}{y\_m}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (fabs (* (- 1.0 z) (/ x y_m)))))
   (if (<= x -9.8e+14)
     t_0
     (if (<= x 3.4e+16) (* (fabs (- (fma x z -4.0) x)) (/ 1.0 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 <= -9.8e+14) {
		tmp = t_0;
	} else if (x <= 3.4e+16) {
		tmp = fabs((fma(x, z, -4.0) - x)) * (1.0 / 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 <= -9.8e+14)
		tmp = t_0;
	elseif (x <= 3.4e+16)
		tmp = Float64(abs(Float64(fma(x, z, -4.0) - x)) * Float64(1.0 / 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, -9.8e+14], t$95$0, If[LessEqual[x, 3.4e+16], N[(N[Abs[N[(N[(x * z + -4.0), $MachinePrecision] - x), $MachinePrecision]], $MachinePrecision] * N[(1.0 / 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 -9.8 \cdot 10^{+14}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 3.4 \cdot 10^{+16}:\\
\;\;\;\;\left|\mathsf{fma}\left(x, z, -4\right) - x\right| \cdot \frac{1}{y\_m}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -9.8e14 or 3.4e16 < x

    1. Initial program 84.2%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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-/.f6499.9

        \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
    5. Applied rewrites99.9%

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

    if -9.8e14 < x < 3.4e16

    1. Initial program 97.8%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites99.9%

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

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

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

        \[\leadsto \left|\color{blue}{\frac{1}{\frac{y}{\mathsf{fma}\left(z, x, -4 - x\right)}}}\right| \]
      4. associate-/r/N/A

        \[\leadsto \left|\color{blue}{\frac{1}{y} \cdot \mathsf{fma}\left(z, x, -4 - x\right)}\right| \]
      5. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{1}{y}} \cdot \mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      6. fabs-mulN/A

        \[\leadsto \color{blue}{\left|\frac{1}{y}\right| \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right|} \]
      7. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{1}{y}}\right| \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      8. inv-powN/A

        \[\leadsto \left|\color{blue}{{y}^{-1}}\right| \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      9. sqr-powN/A

        \[\leadsto \left|\color{blue}{{y}^{\left(\frac{-1}{2}\right)} \cdot {y}^{\left(\frac{-1}{2}\right)}}\right| \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      10. fabs-sqrN/A

        \[\leadsto \color{blue}{\left({y}^{\left(\frac{-1}{2}\right)} \cdot {y}^{\left(\frac{-1}{2}\right)}\right)} \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      11. sqr-powN/A

        \[\leadsto \color{blue}{{y}^{-1}} \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      12. inv-powN/A

        \[\leadsto \color{blue}{\frac{1}{y}} \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      13. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{y}} \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right| \]
      14. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{1}{y} \cdot \left|\mathsf{fma}\left(z, x, -4 - x\right)\right|} \]
      15. lift-fma.f64N/A

        \[\leadsto \frac{1}{y} \cdot \left|\color{blue}{z \cdot x + \left(-4 - x\right)}\right| \]
      16. lift-*.f64N/A

        \[\leadsto \frac{1}{y} \cdot \left|\color{blue}{z \cdot x} + \left(-4 - x\right)\right| \]
      17. lift--.f64N/A

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

        \[\leadsto \frac{1}{y} \cdot \left|\color{blue}{\left(z \cdot x + -4\right) - x}\right| \]
      19. fabs-subN/A

        \[\leadsto \frac{1}{y} \cdot \color{blue}{\left|x - \left(z \cdot x + -4\right)\right|} \]
      20. lower-fabs.f64N/A

        \[\leadsto \frac{1}{y} \cdot \color{blue}{\left|x - \left(z \cdot x + -4\right)\right|} \]
      21. lower--.f64N/A

        \[\leadsto \frac{1}{y} \cdot \left|\color{blue}{x - \left(z \cdot x + -4\right)}\right| \]
      22. lift-*.f64N/A

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

        \[\leadsto \frac{1}{y} \cdot \left|x - \left(\color{blue}{x \cdot z} + -4\right)\right| \]
      24. lower-fma.f6452.8

        \[\leadsto \frac{1}{y} \cdot \left|x - \color{blue}{\mathsf{fma}\left(x, z, -4\right)}\right| \]
    6. Applied rewrites52.8%

      \[\leadsto \color{blue}{\frac{1}{y} \cdot \left|x - \mathsf{fma}\left(x, z, -4\right)\right|} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -9.8 \cdot 10^{+14}:\\ \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\ \mathbf{elif}\;x \leq 3.4 \cdot 10^{+16}:\\ \;\;\;\;\left|\mathsf{fma}\left(x, z, -4\right) - x\right| \cdot \frac{1}{y}\\ \mathbf{else}:\\ \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.3% accurate, 0.5× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \frac{4 + x}{y\_m}\\ t_1 := \frac{x}{y\_m} \cdot z\\ \mathbf{if}\;t\_0 - t\_1 \leq \infty:\\ \;\;\;\;\left|t\_1 - t\_0\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{-x}{y\_m}\right|\\ \end{array} \end{array} \]
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) INFINITY) (fabs (- t_1 t_0)) (fabs (/ (- 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) <= ((double) INFINITY)) {
		tmp = fabs((t_1 - t_0));
	} else {
		tmp = fabs((-x / y_m));
	}
	return tmp;
}
y_m = Math.abs(y);
public static 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) <= Double.POSITIVE_INFINITY) {
		tmp = Math.abs((t_1 - t_0));
	} else {
		tmp = Math.abs((-x / y_m));
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z):
	t_0 = (4.0 + x) / y_m
	t_1 = (x / y_m) * z
	tmp = 0
	if (t_0 - t_1) <= math.inf:
		tmp = math.fabs((t_1 - t_0))
	else:
		tmp = math.fabs((-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) <= Inf)
		tmp = abs(Float64(t_1 - t_0));
	else
		tmp = abs(Float64(Float64(-x) / y_m));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z)
	t_0 = (4.0 + x) / y_m;
	t_1 = (x / y_m) * z;
	tmp = 0.0;
	if ((t_0 - t_1) <= Inf)
		tmp = abs((t_1 - t_0));
	else
		tmp = abs((-x / y_m));
	end
	tmp_2 = 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], Infinity], N[Abs[N[(t$95$1 - t$95$0), $MachinePrecision]], $MachinePrecision], N[Abs[N[((-x) / 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 \infty:\\
\;\;\;\;\left|t\_1 - t\_0\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\frac{-x}{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)) < +inf.0

    1. Initial program 98.7%

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

    if +inf.0 < (-.f64 (/.f64 (+.f64 x #s(literal 4 binary64)) y) (*.f64 (/.f64 x y) z))

    1. Initial program 0.0%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites100.0%

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
    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--.f64100.0

        \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
    7. Applied rewrites100.0%

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

      \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
    9. Step-by-step derivation
      1. Applied rewrites100.0%

        \[\leadsto \left|\frac{-x}{y}\right| \]
    10. Recombined 2 regimes into one program.
    11. Final simplification98.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{4 + x}{y} - \frac{x}{y} \cdot z \leq \infty:\\ \;\;\;\;\left|\frac{x}{y} \cdot z - \frac{4 + x}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{-x}{y}\right|\\ \end{array} \]
    12. Add Preprocessing

    Alternative 3: 99.6% accurate, 0.9× speedup?

    \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 10^{-79}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\mathsf{fma}\left(-x, \frac{z}{y\_m}, \frac{4 + x}{y\_m}\right)\right|\\ \end{array} \end{array} \]
    y_m = (fabs.f64 y)
    (FPCore (x y_m z)
     :precision binary64
     (if (<= y_m 1e-79)
       (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 <= 1e-79) {
    		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 <= 1e-79)
    		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, 1e-79], 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 10^{-79}:\\
    \;\;\;\;\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 < 1e-79

      1. Initial program 88.7%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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 rewrites98.8%

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

      if 1e-79 < y

      1. Initial program 95.5%

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

          \[\leadsto \left|\mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(x\right)}, \frac{z}{y}, \frac{x + 4}{y}\right)\right| \]
        11. lower-/.f6499.9

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

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

          \[\leadsto \left|\mathsf{fma}\left(\mathsf{neg}\left(x\right), \frac{z}{y}, \frac{\color{blue}{4 + x}}{y}\right)\right| \]
        14. lower-+.f6499.9

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

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

    Alternative 4: 99.9% accurate, 1.0× speedup?

    \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -9.8 \cdot 10^{+14}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 1.75 \cdot 10^{+20}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    y_m = (fabs.f64 y)
    (FPCore (x y_m z)
     :precision binary64
     (let* ((t_0 (fabs (* (- 1.0 z) (/ x y_m)))))
       (if (<= x -9.8e+14)
         t_0
         (if (<= x 1.75e+20) (fabs (/ (fma z x (- -4.0 x)) 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 <= -9.8e+14) {
    		tmp = t_0;
    	} else if (x <= 1.75e+20) {
    		tmp = fabs((fma(z, x, (-4.0 - x)) / 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 <= -9.8e+14)
    		tmp = t_0;
    	elseif (x <= 1.75e+20)
    		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / 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, -9.8e+14], t$95$0, If[LessEqual[x, 1.75e+20], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $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 -9.8 \cdot 10^{+14}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 1.75 \cdot 10^{+20}:\\
    \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -9.8e14 or 1.75e20 < x

      1. Initial program 84.2%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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-/.f6499.9

          \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
      5. Applied rewrites99.9%

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

      if -9.8e14 < x < 1.75e20

      1. Initial program 97.8%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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 rewrites99.9%

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

    Alternative 5: 97.9% accurate, 1.1× speedup?

    \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 5.6 \cdot 10^{-26}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    y_m = (fabs.f64 y)
    (FPCore (x y_m z)
     :precision binary64
     (let* ((t_0 (fabs (* (- 1.0 z) (/ x y_m)))))
       (if (<= x -1.55)
         t_0
         (if (<= x 5.6e-26) (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 <= -1.55) {
    		tmp = t_0;
    	} else if (x <= 5.6e-26) {
    		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 <= -1.55)
    		tmp = t_0;
    	elseif (x <= 5.6e-26)
    		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, -1.55], t$95$0, If[LessEqual[x, 5.6e-26], 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 -1.55:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 5.6 \cdot 10^{-26}:\\
    \;\;\;\;\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 < -1.55000000000000004 or 5.6000000000000002e-26 < x

      1. Initial program 85.5%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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-/.f6499.0

          \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
      5. Applied rewrites99.0%

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

      if -1.55000000000000004 < x < 5.6000000000000002e-26

      1. Initial program 97.5%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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 rewrites99.9%

        \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
      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 rewrites99.7%

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

      Alternative 6: 95.0% accurate, 1.1× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{if}\;z \leq -2.2 \cdot 10^{+15}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.6:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      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 -2.2e+15) t_0 (if (<= z 2.6) (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 <= -2.2e+15) {
      		tmp = t_0;
      	} else if (z <= 2.6) {
      		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 <= -2.2e+15)
      		tmp = t_0;
      	elseif (z <= 2.6)
      		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, -2.2e+15], t$95$0, If[LessEqual[z, 2.6], 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 -2.2 \cdot 10^{+15}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;z \leq 2.6:\\
      \;\;\;\;\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 < -2.2e15 or 2.60000000000000009 < z

        1. Initial program 89.2%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 rewrites91.2%

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
        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 rewrites90.1%

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

          if -2.2e15 < z < 2.60000000000000009

          1. Initial program 92.9%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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-eval98.7

              \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
          5. Applied rewrites98.7%

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

        Alternative 7: 85.1% accurate, 1.2× speedup?

        \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;z \leq -1.3 \cdot 10^{+25}:\\ \;\;\;\;\left|\frac{x \cdot z}{y\_m}\right|\\ \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y\_m} \cdot z\right|\\ \end{array} \end{array} \]
        y_m = (fabs.f64 y)
        (FPCore (x y_m z)
         :precision binary64
         (if (<= z -1.3e+25)
           (fabs (/ (* x z) y_m))
           (if (<= z 9.5e+69) (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 <= -1.3e+25) {
        		tmp = fabs(((x * z) / y_m));
        	} else if (z <= 9.5e+69) {
        		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 <= (-1.3d+25)) then
                tmp = abs(((x * z) / y_m))
            else if (z <= 9.5d+69) 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 <= -1.3e+25) {
        		tmp = Math.abs(((x * z) / y_m));
        	} else if (z <= 9.5e+69) {
        		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 <= -1.3e+25:
        		tmp = math.fabs(((x * z) / y_m))
        	elif z <= 9.5e+69:
        		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 <= -1.3e+25)
        		tmp = abs(Float64(Float64(x * z) / y_m));
        	elseif (z <= 9.5e+69)
        		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 <= -1.3e+25)
        		tmp = abs(((x * z) / y_m));
        	elseif (z <= 9.5e+69)
        		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, -1.3e+25], N[Abs[N[(N[(x * z), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], If[LessEqual[z, 9.5e+69], 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 -1.3 \cdot 10^{+25}:\\
        \;\;\;\;\left|\frac{x \cdot z}{y\_m}\right|\\
        
        \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\
        \;\;\;\;\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 < -1.2999999999999999e25

          1. Initial program 96.4%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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 rewrites96.5%

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

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

              \[\leadsto \left|\frac{\color{blue}{z \cdot x}}{y}\right| \]
            2. lower-*.f6476.4

              \[\leadsto \left|\frac{\color{blue}{z \cdot x}}{y}\right| \]
          7. Applied rewrites76.4%

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

          if -1.2999999999999999e25 < z < 9.4999999999999995e69

          1. Initial program 92.4%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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-eval94.5

              \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
          5. Applied rewrites94.5%

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

          if 9.4999999999999995e69 < z

          1. Initial program 81.9%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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 rewrites84.6%

            \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
          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--.f6435.2

              \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
          7. Applied rewrites35.2%

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

            \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
          9. Step-by-step derivation
            1. Applied rewrites20.7%

              \[\leadsto \left|\frac{-x}{y}\right| \]
            2. Taylor expanded in z around inf

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

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

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

                \[\leadsto \left|\color{blue}{z \cdot \frac{x}{y}}\right| \]
              4. lower-/.f6483.3

                \[\leadsto \left|z \cdot \color{blue}{\frac{x}{y}}\right| \]
            4. Applied rewrites83.3%

              \[\leadsto \left|\color{blue}{z \cdot \frac{x}{y}}\right| \]
          10. Recombined 3 regimes into one program.
          11. Final simplification88.1%

            \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.3 \cdot 10^{+25}:\\ \;\;\;\;\left|\frac{x \cdot z}{y}\right|\\ \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \end{array} \]
          12. Add Preprocessing

          Alternative 8: 86.3% accurate, 1.2× speedup?

          \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{x}{y\_m} \cdot z\right|\\ \mathbf{if}\;z \leq -7.8 \cdot 10^{+24}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
          y_m = (fabs.f64 y)
          (FPCore (x y_m z)
           :precision binary64
           (let* ((t_0 (fabs (* (/ x y_m) z))))
             (if (<= z -7.8e+24) t_0 (if (<= z 9.5e+69) (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 <= -7.8e+24) {
          		tmp = t_0;
          	} else if (z <= 9.5e+69) {
          		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 <= (-7.8d+24)) then
                  tmp = t_0
              else if (z <= 9.5d+69) 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 <= -7.8e+24) {
          		tmp = t_0;
          	} else if (z <= 9.5e+69) {
          		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 <= -7.8e+24:
          		tmp = t_0
          	elif z <= 9.5e+69:
          		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 <= -7.8e+24)
          		tmp = t_0;
          	elseif (z <= 9.5e+69)
          		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 <= -7.8e+24)
          		tmp = t_0;
          	elseif (z <= 9.5e+69)
          		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, -7.8e+24], t$95$0, If[LessEqual[z, 9.5e+69], 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 -7.8 \cdot 10^{+24}:\\
          \;\;\;\;t\_0\\
          
          \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\
          \;\;\;\;\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 < -7.7999999999999995e24 or 9.4999999999999995e69 < z

            1. Initial program 89.3%

              \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
            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 rewrites90.6%

              \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
            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--.f6436.5

                \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
            7. Applied rewrites36.5%

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

              \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
            9. Step-by-step derivation
              1. Applied rewrites19.6%

                \[\leadsto \left|\frac{-x}{y}\right| \]
              2. Taylor expanded in z around inf

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

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

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

                  \[\leadsto \left|\color{blue}{z \cdot \frac{x}{y}}\right| \]
                4. lower-/.f6479.8

                  \[\leadsto \left|z \cdot \color{blue}{\frac{x}{y}}\right| \]
              4. Applied rewrites79.8%

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

              if -7.7999999999999995e24 < z < 9.4999999999999995e69

              1. Initial program 92.4%

                \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
              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-eval94.5

                  \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
              5. Applied rewrites94.5%

                \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
            10. Recombined 2 regimes into one program.
            11. Final simplification88.1%

              \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -7.8 \cdot 10^{+24}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \mathbf{elif}\;z \leq 9.5 \cdot 10^{+69}:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \end{array} \]
            12. Add Preprocessing

            Alternative 9: 69.1% accurate, 1.3× speedup?

            \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{-x}{y\_m}\right|\\ \mathbf{if}\;x \leq -1.52:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
            y_m = (fabs.f64 y)
            (FPCore (x y_m z)
             :precision binary64
             (let* ((t_0 (fabs (/ (- x) y_m))))
               (if (<= x -1.52) 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 <= -1.52) {
            		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 <= (-1.52d0)) 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 <= -1.52) {
            		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 <= -1.52:
            		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 <= -1.52)
            		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 <= -1.52)
            		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, -1.52], 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 -1.52:\\
            \;\;\;\;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 < -1.52 or 4 < x

              1. Initial program 84.9%

                \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
              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 rewrites91.5%

                \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
              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--.f6466.4

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

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

                \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
              9. Step-by-step derivation
                1. Applied rewrites65.8%

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

                if -1.52 < x < 4

                1. Initial program 97.7%

                  \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
                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-/.f6472.4

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

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

              Alternative 10: 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 91.0%

                \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
              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-eval69.3

                  \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
              5. Applied rewrites69.3%

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

              Alternative 11: 40.2% 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 91.0%

                \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
              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-/.f6437.5

                  \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
              5. Applied rewrites37.5%

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

              Reproduce

              ?
              herbie shell --seed 2024235 
              (FPCore (x y z)
                :name "fabs fraction 1"
                :precision binary64
                (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))