fabs fraction 1

Percentage Accurate: 91.5% → 99.8%
Time: 7.5s
Alternatives: 9
Speedup: 1.2×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 9 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 91.5% 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: 99.8% accurate, 0.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 1.4 \cdot 10^{+47}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\mathsf{fma}\left(-x, \frac{z}{y\_m}, \frac{4 + x}{y\_m}\right)\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (if (<= y_m 1.4e+47)
   (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 <= 1.4e+47) {
		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 <= 1.4e+47)
		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, 1.4e+47], 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 1.4 \cdot 10^{+47}:\\
\;\;\;\;\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 < 1.39999999999999994e47

    1. Initial program 94.4%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites96.7%

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

    if 1.39999999999999994e47 < y

    1. Initial program 99.9%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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-/.f6499.7

        \[\leadsto \left|\mathsf{fma}\left(-x, \color{blue}{\frac{z}{y}}, \frac{x + 4}{y}\right)\right| \]
      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-+.f6499.7

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

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

Alternative 2: 97.4% accurate, 0.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 8 \cdot 10^{+102}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y\_m} \cdot z - \frac{4 + x}{y\_m}\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (if (<= y_m 8e+102)
   (fabs (/ (fma z x (- -4.0 x)) y_m))
   (fabs (- (* (/ x y_m) z) (/ (+ 4.0 x) y_m)))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double tmp;
	if (y_m <= 8e+102) {
		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
	} else {
		tmp = fabs((((x / y_m) * z) - ((4.0 + x) / y_m)));
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	tmp = 0.0
	if (y_m <= 8e+102)
		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
	else
		tmp = abs(Float64(Float64(Float64(x / y_m) * z) - 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, 8e+102], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(N[(x / y$95$m), $MachinePrecision] * z), $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 8 \cdot 10^{+102}:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\frac{x}{y\_m} \cdot z - \frac{4 + x}{y\_m}\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 7.99999999999999982e102

    1. Initial program 94.7%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites96.9%

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

    if 7.99999999999999982e102 < y

    1. Initial program 99.9%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification97.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 8 \cdot 10^{+102}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z - \frac{4 + x}{y}\right|\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 93.5% accurate, 0.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{if}\;z \leq -1.85 \cdot 10^{+154}:\\ \;\;\;\;\left|\frac{x}{y\_m} \cdot z\right|\\ \mathbf{elif}\;z \leq -1.05 \cdot 10^{+19}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 6.5 \cdot 10^{-10}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
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 -1.85e+154)
     (fabs (* (/ x y_m) z))
     (if (<= z -1.05e+19)
       t_0
       (if (<= z 6.5e-10) (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 <= -1.85e+154) {
		tmp = fabs(((x / y_m) * z));
	} else if (z <= -1.05e+19) {
		tmp = t_0;
	} else if (z <= 6.5e-10) {
		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 <= -1.85e+154)
		tmp = abs(Float64(Float64(x / y_m) * z));
	elseif (z <= -1.05e+19)
		tmp = t_0;
	elseif (z <= 6.5e-10)
		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, -1.85e+154], N[Abs[N[(N[(x / y$95$m), $MachinePrecision] * z), $MachinePrecision]], $MachinePrecision], If[LessEqual[z, -1.05e+19], t$95$0, If[LessEqual[z, 6.5e-10], 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 -1.85 \cdot 10^{+154}:\\
\;\;\;\;\left|\frac{x}{y\_m} \cdot z\right|\\

\mathbf{elif}\;z \leq -1.05 \cdot 10^{+19}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;z \leq 6.5 \cdot 10^{-10}:\\
\;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if z < -1.84999999999999997e154

    1. Initial program 97.2%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites81.6%

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

      \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}}\right| \]
    6. Step-by-step derivation
      1. *-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-/.f6497.1

        \[\leadsto \left|z \cdot \color{blue}{\frac{x}{y}}\right| \]
    7. Applied rewrites97.1%

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

    if -1.84999999999999997e154 < z < -1.05e19 or 6.5000000000000003e-10 < z

    1. Initial program 95.0%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    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 rewrites94.6%

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
    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 rewrites93.5%

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

      if -1.05e19 < z < 6.5000000000000003e-10

      1. Initial program 95.4%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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-eval98.9

          \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
      5. Applied rewrites98.9%

        \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
    7. Recombined 3 regimes into one program.
    8. Final simplification96.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.85 \cdot 10^{+154}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \mathbf{elif}\;z \leq -1.05 \cdot 10^{+19}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y}\right|\\ \mathbf{elif}\;z \leq 6.5 \cdot 10^{-10}:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y}\right|\\ \end{array} \]
    9. Add Preprocessing

    Alternative 4: 98.7% accurate, 1.1× speedup?

    \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -430:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 0.0032:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    y_m = (fabs.f64 y)
    (FPCore (x y_m z)
     :precision binary64
     (let* ((t_0 (fabs (* (- 1.0 z) (/ x y_m)))))
       (if (<= x -430.0)
         t_0
         (if (<= x 0.0032) (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 <= -430.0) {
    		tmp = t_0;
    	} else if (x <= 0.0032) {
    		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 <= -430.0)
    		tmp = t_0;
    	elseif (x <= 0.0032)
    		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, -430.0], t$95$0, If[LessEqual[x, 0.0032], 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 -430:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 0.0032:\\
    \;\;\;\;\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 < -430 or 0.00320000000000000015 < x

      1. Initial program 92.2%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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-/.f6498.9

          \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
      5. Applied rewrites98.9%

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

      if -430 < x < 0.00320000000000000015

      1. Initial program 98.3%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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 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 5: 84.6% accurate, 1.2× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{x}{y\_m} \cdot z\right|\\ \mathbf{if}\;z \leq -5.2 \cdot 10^{+137}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.25 \cdot 10^{+74}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (let* ((t_0 (fabs (* (/ x y_m) z))))
         (if (<= z -5.2e+137)
           t_0
           (if (<= z 2.25e+74) (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 <= -5.2e+137) {
      		tmp = t_0;
      	} else if (z <= 2.25e+74) {
      		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 <= (-5.2d+137)) then
              tmp = t_0
          else if (z <= 2.25d+74) 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 <= -5.2e+137) {
      		tmp = t_0;
      	} else if (z <= 2.25e+74) {
      		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 <= -5.2e+137:
      		tmp = t_0
      	elif z <= 2.25e+74:
      		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 <= -5.2e+137)
      		tmp = t_0;
      	elseif (z <= 2.25e+74)
      		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 <= -5.2e+137)
      		tmp = t_0;
      	elseif (z <= 2.25e+74)
      		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, -5.2e+137], t$95$0, If[LessEqual[z, 2.25e+74], 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 -5.2 \cdot 10^{+137}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;z \leq 2.25 \cdot 10^{+74}:\\
      \;\;\;\;\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 < -5.1999999999999998e137 or 2.25e74 < z

        1. Initial program 94.5%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 rewrites87.0%

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

          \[\leadsto \left|\color{blue}{\frac{x \cdot z}{y}}\right| \]
        6. Step-by-step derivation
          1. *-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-/.f6487.5

            \[\leadsto \left|z \cdot \color{blue}{\frac{x}{y}}\right| \]
        7. Applied rewrites87.5%

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

        if -5.1999999999999998e137 < z < 2.25e74

        1. Initial program 96.0%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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-eval90.3

            \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
        5. Applied rewrites90.3%

          \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
      3. Recombined 2 regimes into one program.
      4. Final simplification89.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -5.2 \cdot 10^{+137}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \mathbf{elif}\;z \leq 2.25 \cdot 10^{+74}:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y} \cdot z\right|\\ \end{array} \]
      5. Add Preprocessing

      Alternative 6: 97.7% accurate, 1.2× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{+25}:\\ \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (if (<= x -5e+25)
         (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 <= -5e+25) {
      		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 <= -5e+25)
      		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, -5e+25], 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 -5 \cdot 10^{+25}:\\
      \;\;\;\;\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 < -5.00000000000000024e25

        1. Initial program 89.7%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 -5.00000000000000024e25 < x

        1. Initial program 96.9%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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 rewrites98.1%

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

      Alternative 7: 68.4% accurate, 1.3× speedup?

      \[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{-x}{y\_m}\right|\\ \mathbf{if}\;x \leq -10.5:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      y_m = (fabs.f64 y)
      (FPCore (x y_m z)
       :precision binary64
       (let* ((t_0 (fabs (/ (- x) y_m))))
         (if (<= x -10.5) 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 <= -10.5) {
      		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 <= (-10.5d0)) 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 <= -10.5) {
      		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 <= -10.5:
      		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 <= -10.5)
      		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 <= -10.5)
      		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, -10.5], 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 -10.5:\\
      \;\;\;\;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 < -10.5 or 4 < x

        1. Initial program 92.3%

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

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
        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--.f6458.3

            \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
        7. Applied rewrites58.3%

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

          \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
        9. Step-by-step derivation
          1. Applied rewrites57.4%

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

          if -10.5 < x < 4

          1. Initial program 98.3%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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-/.f6477.3

              \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
          5. Applied rewrites77.3%

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

        Alternative 8: 69.5% 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 95.5%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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-eval68.6

            \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
        5. Applied rewrites68.6%

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

        Alternative 9: 39.3% 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 95.5%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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-/.f6444.1

            \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        5. Applied rewrites44.1%

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

        Reproduce

        ?
        herbie shell --seed 2024257 
        (FPCore (x y z)
          :name "fabs fraction 1"
          :precision binary64
          (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))