fabs fraction 1

Percentage Accurate: 92.0% → 95.7%
Time: 7.8s
Alternatives: 6
Speedup: 1.6×

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 6 alternatives:

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

Initial Program: 92.0% 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: 95.7% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \left|\frac{\mathsf{fma}\left(x, z, -4 - x\right)}{y}\right| \end{array} \]
(FPCore (x y z) :precision binary64 (fabs (/ (fma x z (- -4.0 x)) y)))
double code(double x, double y, double z) {
	return fabs((fma(x, z, (-4.0 - x)) / y));
}
function code(x, y, z)
	return abs(Float64(fma(x, z, Float64(-4.0 - x)) / y))
end
code[x_, y_, z_] := N[Abs[N[(N[(x * z + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\left|\frac{\mathsf{fma}\left(x, z, -4 - x\right)}{y}\right|
\end{array}
Derivation
  1. Initial program 89.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{\left(\mathsf{neg}\left(4\right)\right) - x}\right)}{y}\right| \]
    23. metadata-eval98.4

      \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{-4} - x\right)}{y}\right| \]
  4. Applied rewrites98.4%

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

Alternative 2: 94.3% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{\mathsf{fma}\left(x, z, -4\right)}{y}\right|\\ \mathbf{if}\;z \leq -4.1 \cdot 10^{+40}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 0.00035:\\ \;\;\;\;\left|\frac{x + 4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (fabs (/ (fma x z -4.0) y))))
   (if (<= z -4.1e+40) t_0 (if (<= z 0.00035) (fabs (/ (+ x 4.0) y)) t_0))))
double code(double x, double y, double z) {
	double t_0 = fabs((fma(x, z, -4.0) / y));
	double tmp;
	if (z <= -4.1e+40) {
		tmp = t_0;
	} else if (z <= 0.00035) {
		tmp = fabs(((x + 4.0) / y));
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x, y, z)
	t_0 = abs(Float64(fma(x, z, -4.0) / y))
	tmp = 0.0
	if (z <= -4.1e+40)
		tmp = t_0;
	elseif (z <= 0.00035)
		tmp = abs(Float64(Float64(x + 4.0) / y));
	else
		tmp = t_0;
	end
	return tmp
end
code[x_, y_, z_] := Block[{t$95$0 = N[Abs[N[(N[(x * z + -4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -4.1e+40], t$95$0, If[LessEqual[z, 0.00035], N[Abs[N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left|\frac{\mathsf{fma}\left(x, z, -4\right)}{y}\right|\\
\mathbf{if}\;z \leq -4.1 \cdot 10^{+40}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;z \leq 0.00035:\\
\;\;\;\;\left|\frac{x + 4}{y}\right|\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -4.1000000000000002e40 or 3.49999999999999996e-4 < z

    1. Initial program 84.3%

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

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

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

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

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

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

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

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

        \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{\left(\mathsf{neg}\left(4\right)\right) - x}\right)}{y}\right| \]
      23. metadata-eval96.6

        \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{-4} - x\right)}{y}\right| \]
    4. Applied rewrites96.6%

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

      \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{-4}\right)}{y}\right| \]
    6. Step-by-step derivation
      1. Applied rewrites95.8%

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

      if -4.1000000000000002e40 < z < 3.49999999999999996e-4

      1. Initial program 94.2%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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. lower-+.f6499.3

          \[\leadsto \left|\frac{\color{blue}{4 + x}}{y}\right| \]
      5. Applied rewrites99.3%

        \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
    7. Recombined 2 regimes into one program.
    8. Final simplification97.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -4.1 \cdot 10^{+40}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(x, z, -4\right)}{y}\right|\\ \mathbf{elif}\;z \leq 0.00035:\\ \;\;\;\;\left|\frac{x + 4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(x, z, -4\right)}{y}\right|\\ \end{array} \]
    9. Add Preprocessing

    Alternative 3: 84.2% accurate, 1.2× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{x \cdot z}{y}\right|\\ \mathbf{if}\;z \leq -8 \cdot 10^{+108}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.6 \cdot 10^{+83}:\\ \;\;\;\;\left|\frac{x + 4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (fabs (/ (* x z) y))))
       (if (<= z -8e+108) t_0 (if (<= z 2.6e+83) (fabs (/ (+ x 4.0) y)) t_0))))
    double code(double x, double y, double z) {
    	double t_0 = fabs(((x * z) / y));
    	double tmp;
    	if (z <= -8e+108) {
    		tmp = t_0;
    	} else if (z <= 2.6e+83) {
    		tmp = fabs(((x + 4.0) / y));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        real(8) :: t_0
        real(8) :: tmp
        t_0 = abs(((x * z) / y))
        if (z <= (-8d+108)) then
            tmp = t_0
        else if (z <= 2.6d+83) then
            tmp = abs(((x + 4.0d0) / y))
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z) {
    	double t_0 = Math.abs(((x * z) / y));
    	double tmp;
    	if (z <= -8e+108) {
    		tmp = t_0;
    	} else if (z <= 2.6e+83) {
    		tmp = Math.abs(((x + 4.0) / y));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	t_0 = math.fabs(((x * z) / y))
    	tmp = 0
    	if z <= -8e+108:
    		tmp = t_0
    	elif z <= 2.6e+83:
    		tmp = math.fabs(((x + 4.0) / y))
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x, y, z)
    	t_0 = abs(Float64(Float64(x * z) / y))
    	tmp = 0.0
    	if (z <= -8e+108)
    		tmp = t_0;
    	elseif (z <= 2.6e+83)
    		tmp = abs(Float64(Float64(x + 4.0) / y));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	t_0 = abs(((x * z) / y));
    	tmp = 0.0;
    	if (z <= -8e+108)
    		tmp = t_0;
    	elseif (z <= 2.6e+83)
    		tmp = abs(((x + 4.0) / y));
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[Abs[N[(N[(x * z), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -8e+108], t$95$0, If[LessEqual[z, 2.6e+83], N[Abs[N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \left|\frac{x \cdot z}{y}\right|\\
    \mathbf{if}\;z \leq -8 \cdot 10^{+108}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;z \leq 2.6 \cdot 10^{+83}:\\
    \;\;\;\;\left|\frac{x + 4}{y}\right|\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if z < -8.0000000000000003e108 or 2.6000000000000001e83 < z

      1. Initial program 85.4%

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

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

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

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

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

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

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

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

          \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{\left(\mathsf{neg}\left(4\right)\right) - x}\right)}{y}\right| \]
        23. metadata-eval95.4

          \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{-4} - x\right)}{y}\right| \]
      4. Applied rewrites95.4%

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

        \[\leadsto \left|\frac{\color{blue}{x \cdot z}}{y}\right| \]
      6. Step-by-step derivation
        1. lower-*.f6471.0

          \[\leadsto \left|\frac{\color{blue}{x \cdot z}}{y}\right| \]
      7. Applied rewrites71.0%

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

      if -8.0000000000000003e108 < z < 2.6000000000000001e83

      1. Initial program 91.8%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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. lower-+.f6493.8

          \[\leadsto \left|\frac{\color{blue}{4 + x}}{y}\right| \]
      5. Applied rewrites93.8%

        \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
    3. Recombined 2 regimes into one program.
    4. Final simplification86.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -8 \cdot 10^{+108}:\\ \;\;\;\;\left|\frac{x \cdot z}{y}\right|\\ \mathbf{elif}\;z \leq 2.6 \cdot 10^{+83}:\\ \;\;\;\;\left|\frac{x + 4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x \cdot z}{y}\right|\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 69.2% accurate, 1.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{-x}{y}\right|\\ \mathbf{if}\;x \leq -1.5:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (fabs (/ (- x) y))))
       (if (<= x -1.5) t_0 (if (<= x 4.0) (fabs (/ 4.0 y)) t_0))))
    double code(double x, double y, double z) {
    	double t_0 = fabs((-x / y));
    	double tmp;
    	if (x <= -1.5) {
    		tmp = t_0;
    	} else if (x <= 4.0) {
    		tmp = fabs((4.0 / y));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        real(8) :: t_0
        real(8) :: tmp
        t_0 = abs((-x / y))
        if (x <= (-1.5d0)) then
            tmp = t_0
        else if (x <= 4.0d0) then
            tmp = abs((4.0d0 / y))
        else
            tmp = t_0
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z) {
    	double t_0 = Math.abs((-x / y));
    	double tmp;
    	if (x <= -1.5) {
    		tmp = t_0;
    	} else if (x <= 4.0) {
    		tmp = Math.abs((4.0 / y));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	t_0 = math.fabs((-x / y))
    	tmp = 0
    	if x <= -1.5:
    		tmp = t_0
    	elif x <= 4.0:
    		tmp = math.fabs((4.0 / y))
    	else:
    		tmp = t_0
    	return tmp
    
    function code(x, y, z)
    	t_0 = abs(Float64(Float64(-x) / y))
    	tmp = 0.0
    	if (x <= -1.5)
    		tmp = t_0;
    	elseif (x <= 4.0)
    		tmp = abs(Float64(4.0 / y));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	t_0 = abs((-x / y));
    	tmp = 0.0;
    	if (x <= -1.5)
    		tmp = t_0;
    	elseif (x <= 4.0)
    		tmp = abs((4.0 / y));
    	else
    		tmp = t_0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[Abs[N[((-x) / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -1.5], t$95$0, If[LessEqual[x, 4.0], N[Abs[N[(4.0 / y), $MachinePrecision]], $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \left|\frac{-x}{y}\right|\\
    \mathbf{if}\;x \leq -1.5:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 4:\\
    \;\;\;\;\left|\frac{4}{y}\right|\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1.5 or 4 < x

      1. Initial program 81.7%

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

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

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

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

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

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

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

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

          \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{\left(\mathsf{neg}\left(4\right)\right) - x}\right)}{y}\right| \]
        23. metadata-eval96.6

          \[\leadsto \left|\frac{\mathsf{fma}\left(x, z, \color{blue}{-4} - x\right)}{y}\right| \]
      4. Applied rewrites96.6%

        \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(x, z, -4 - x\right)}{y}\right|} \]
      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--.f6469.0

          \[\leadsto \left|\frac{\color{blue}{-4 - x}}{y}\right| \]
      7. Applied rewrites69.0%

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

        \[\leadsto \left|\frac{-1 \cdot \color{blue}{x}}{y}\right| \]
      9. Step-by-step derivation
        1. Applied rewrites67.6%

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

        if -1.5 < x < 4

        1. Initial program 96.1%

          \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
        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-/.f6480.4

            \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
        5. Applied rewrites80.4%

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

      Alternative 5: 70.1% accurate, 2.1× speedup?

      \[\begin{array}{l} \\ \left|\frac{x + 4}{y}\right| \end{array} \]
      (FPCore (x y z) :precision binary64 (fabs (/ (+ x 4.0) y)))
      double code(double x, double y, double z) {
      	return fabs(((x + 4.0) / y));
      }
      
      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))
      end function
      
      public static double code(double x, double y, double z) {
      	return Math.abs(((x + 4.0) / y));
      }
      
      def code(x, y, z):
      	return math.fabs(((x + 4.0) / y))
      
      function code(x, y, z)
      	return abs(Float64(Float64(x + 4.0) / y))
      end
      
      function tmp = code(x, y, z)
      	tmp = abs(((x + 4.0) / y));
      end
      
      code[x_, y_, z_] := N[Abs[N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left|\frac{x + 4}{y}\right|
      \end{array}
      
      Derivation
      1. Initial program 89.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

          \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
        13. lower-+.f6475.7

          \[\leadsto \left|\frac{\color{blue}{4 + x}}{y}\right| \]
      5. Applied rewrites75.7%

        \[\leadsto \left|\color{blue}{\frac{4 + x}{y}}\right| \]
      6. Final simplification75.7%

        \[\leadsto \left|\frac{x + 4}{y}\right| \]
      7. Add Preprocessing

      Alternative 6: 40.2% accurate, 2.6× speedup?

      \[\begin{array}{l} \\ \left|\frac{4}{y}\right| \end{array} \]
      (FPCore (x y z) :precision binary64 (fabs (/ 4.0 y)))
      double code(double x, double y, double z) {
      	return fabs((4.0 / y));
      }
      
      real(8) function code(x, y, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          code = abs((4.0d0 / y))
      end function
      
      public static double code(double x, double y, double z) {
      	return Math.abs((4.0 / y));
      }
      
      def code(x, y, z):
      	return math.fabs((4.0 / y))
      
      function code(x, y, z)
      	return abs(Float64(4.0 / y))
      end
      
      function tmp = code(x, y, z)
      	tmp = abs((4.0 / y));
      end
      
      code[x_, y_, z_] := N[Abs[N[(4.0 / y), $MachinePrecision]], $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left|\frac{4}{y}\right|
      \end{array}
      
      Derivation
      1. Initial program 89.6%

        \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
      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-/.f6447.0

          \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
      5. Applied rewrites47.0%

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

      Reproduce

      ?
      herbie shell --seed 2024226 
      (FPCore (x y z)
        :name "fabs fraction 1"
        :precision binary64
        (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))