fabs fraction 1

Percentage Accurate: 91.4% → 97.8%
Time: 5.2s
Alternatives: 8
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 8 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: 91.4% 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: 97.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{4 + x}{y}\\ t_1 := z \cdot \frac{x}{y}\\ \mathbf{if}\;t\_0 - t\_1 \leq \infty:\\ \;\;\;\;\left|t\_1 - t\_0\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y}\right|\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (/ (+ 4.0 x) y)) (t_1 (* z (/ x y))))
   (if (<= (- t_0 t_1) INFINITY) (fabs (- t_1 t_0)) (fabs (/ x y)))))
double code(double x, double y, double z) {
	double t_0 = (4.0 + x) / y;
	double t_1 = z * (x / y);
	double tmp;
	if ((t_0 - t_1) <= ((double) INFINITY)) {
		tmp = fabs((t_1 - t_0));
	} else {
		tmp = fabs((x / y));
	}
	return tmp;
}
public static double code(double x, double y, double z) {
	double t_0 = (4.0 + x) / y;
	double t_1 = z * (x / y);
	double tmp;
	if ((t_0 - t_1) <= Double.POSITIVE_INFINITY) {
		tmp = Math.abs((t_1 - t_0));
	} else {
		tmp = Math.abs((x / y));
	}
	return tmp;
}
def code(x, y, z):
	t_0 = (4.0 + x) / y
	t_1 = z * (x / y)
	tmp = 0
	if (t_0 - t_1) <= math.inf:
		tmp = math.fabs((t_1 - t_0))
	else:
		tmp = math.fabs((x / y))
	return tmp
function code(x, y, z)
	t_0 = Float64(Float64(4.0 + x) / y)
	t_1 = Float64(z * Float64(x / y))
	tmp = 0.0
	if (Float64(t_0 - t_1) <= Inf)
		tmp = abs(Float64(t_1 - t_0));
	else
		tmp = abs(Float64(x / y));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = (4.0 + x) / y;
	t_1 = z * (x / y);
	tmp = 0.0;
	if ((t_0 - t_1) <= Inf)
		tmp = abs((t_1 - t_0));
	else
		tmp = abs((x / y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(4.0 + x), $MachinePrecision] / y), $MachinePrecision]}, Block[{t$95$1 = N[(z * N[(x / y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(t$95$0 - t$95$1), $MachinePrecision], Infinity], N[Abs[N[(t$95$1 - t$95$0), $MachinePrecision]], $MachinePrecision], N[Abs[N[(x / y), $MachinePrecision]], $MachinePrecision]]]]
\begin{array}{l}

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

\mathbf{else}:\\
\;\;\;\;\left|\frac{x}{y}\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 (+.f64 x #s(literal 4 binary64)) y) (*.f64 (/.f64 x y) z)) < +inf.0

    1. Initial program 99.4%

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

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

    1. Initial program 0.0%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Add Preprocessing
    3. 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-eval100.0

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

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

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

        \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
    8. Recombined 2 regimes into one program.
    9. Final simplification99.5%

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

    Alternative 2: 98.8% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\ \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4.2:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (let* ((t_0 (fabs (* (- 1.0 z) (/ x y)))))
       (if (<= x -1.55) t_0 (if (<= x 4.2) (fabs (/ (fma z x -4.0) y)) t_0))))
    double code(double x, double y, double z) {
    	double t_0 = fabs(((1.0 - z) * (x / y)));
    	double tmp;
    	if (x <= -1.55) {
    		tmp = t_0;
    	} else if (x <= 4.2) {
    		tmp = fabs((fma(z, x, -4.0) / y));
    	} else {
    		tmp = t_0;
    	}
    	return tmp;
    }
    
    function code(x, y, z)
    	t_0 = abs(Float64(Float64(1.0 - z) * Float64(x / y)))
    	tmp = 0.0
    	if (x <= -1.55)
    		tmp = t_0;
    	elseif (x <= 4.2)
    		tmp = abs(Float64(fma(z, x, -4.0) / y));
    	else
    		tmp = t_0;
    	end
    	return tmp
    end
    
    code[x_, y_, z_] := Block[{t$95$0 = N[Abs[N[(N[(1.0 - z), $MachinePrecision] * N[(x / y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -1.55], t$95$0, If[LessEqual[x, 4.2], N[Abs[N[(N[(z * x + -4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision], t$95$0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\
    \mathbf{if}\;x \leq -1.55:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;x \leq 4.2:\\
    \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y}\right|\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if x < -1.55000000000000004 or 4.20000000000000018 < x

      1. Initial program 89.3%

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

          \[\leadsto \left|\left(1 - z\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
      5. Applied rewrites99.4%

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

      if -1.55000000000000004 < x < 4.20000000000000018

      1. Initial program 98.9%

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

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

        \[\leadsto \left|\frac{\mathsf{fma}\left(z, x, \color{blue}{-4}\right)}{y}\right| \]
      6. Step-by-step derivation
        1. Applied rewrites98.8%

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

      Alternative 3: 94.3% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{\mathsf{fma}\left(z, x, -4\right)}{y}\right|\\ \mathbf{if}\;z \leq -3.35 \cdot 10^{+44}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 0.18:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      (FPCore (x y z)
       :precision binary64
       (let* ((t_0 (fabs (/ (fma z x -4.0) y))))
         (if (<= z -3.35e+44) t_0 (if (<= z 0.18) (fabs (/ (- x -4.0) y)) t_0))))
      double code(double x, double y, double z) {
      	double t_0 = fabs((fma(z, x, -4.0) / y));
      	double tmp;
      	if (z <= -3.35e+44) {
      		tmp = t_0;
      	} else if (z <= 0.18) {
      		tmp = fabs(((x - -4.0) / y));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      function code(x, y, z)
      	t_0 = abs(Float64(fma(z, x, -4.0) / y))
      	tmp = 0.0
      	if (z <= -3.35e+44)
      		tmp = t_0;
      	elseif (z <= 0.18)
      		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[(z * x + -4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -3.35e+44], t$95$0, If[LessEqual[z, 0.18], 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(z, x, -4\right)}{y}\right|\\
      \mathbf{if}\;z \leq -3.35 \cdot 10^{+44}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;z \leq 0.18:\\
      \;\;\;\;\left|\frac{x - -4}{y}\right|\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_0\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if z < -3.35000000000000018e44 or 0.17999999999999999 < z

        1. Initial program 93.6%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

            \[\leadsto \left|\color{blue}{\frac{x \cdot z - \left(x + 4\right)}{y}}\right| \]
        4. Applied rewrites93.3%

          \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]
        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 rewrites92.7%

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

          if -3.35000000000000018e44 < z < 0.17999999999999999

          1. Initial program 94.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
            18. metadata-eval100.0

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

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

        Alternative 4: 84.0% accurate, 1.2× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{z \cdot x}{y}\right|\\ \mathbf{if}\;z \leq -5 \cdot 10^{+44}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.2 \cdot 10^{+20}:\\ \;\;\;\;\left|\frac{x - -4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
        (FPCore (x y z)
         :precision binary64
         (let* ((t_0 (fabs (/ (* z x) y))))
           (if (<= z -5e+44) t_0 (if (<= z 2.2e+20) (fabs (/ (- x -4.0) y)) t_0))))
        double code(double x, double y, double z) {
        	double t_0 = fabs(((z * x) / y));
        	double tmp;
        	if (z <= -5e+44) {
        		tmp = t_0;
        	} else if (z <= 2.2e+20) {
        		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(((z * x) / y))
            if (z <= (-5d+44)) then
                tmp = t_0
            else if (z <= 2.2d+20) 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(((z * x) / y));
        	double tmp;
        	if (z <= -5e+44) {
        		tmp = t_0;
        	} else if (z <= 2.2e+20) {
        		tmp = Math.abs(((x - -4.0) / y));
        	} else {
        		tmp = t_0;
        	}
        	return tmp;
        }
        
        def code(x, y, z):
        	t_0 = math.fabs(((z * x) / y))
        	tmp = 0
        	if z <= -5e+44:
        		tmp = t_0
        	elif z <= 2.2e+20:
        		tmp = math.fabs(((x - -4.0) / y))
        	else:
        		tmp = t_0
        	return tmp
        
        function code(x, y, z)
        	t_0 = abs(Float64(Float64(z * x) / y))
        	tmp = 0.0
        	if (z <= -5e+44)
        		tmp = t_0;
        	elseif (z <= 2.2e+20)
        		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(((z * x) / y));
        	tmp = 0.0;
        	if (z <= -5e+44)
        		tmp = t_0;
        	elseif (z <= 2.2e+20)
        		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[(z * x), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -5e+44], t$95$0, If[LessEqual[z, 2.2e+20], N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision], t$95$0]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \left|\frac{z \cdot x}{y}\right|\\
        \mathbf{if}\;z \leq -5 \cdot 10^{+44}:\\
        \;\;\;\;t\_0\\
        
        \mathbf{elif}\;z \leq 2.2 \cdot 10^{+20}:\\
        \;\;\;\;\left|\frac{x - -4}{y}\right|\\
        
        \mathbf{else}:\\
        \;\;\;\;t\_0\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if z < -4.9999999999999996e44 or 2.2e20 < z

          1. Initial program 94.0%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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 rewrites92.8%

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

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

              \[\leadsto \left|\frac{\color{blue}{z \cdot x}}{y}\right| \]
            2. lower-*.f6472.7

              \[\leadsto \left|\frac{\color{blue}{z \cdot x}}{y}\right| \]
          7. Applied rewrites72.7%

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

          if -4.9999999999999996e44 < z < 2.2e20

          1. Initial program 93.9%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
            18. metadata-eval99.4

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

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

        Alternative 5: 97.8% accurate, 1.2× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -8 \cdot 10^{+72}:\\ \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|\\ \end{array} \end{array} \]
        (FPCore (x y z)
         :precision binary64
         (if (<= x -8e+72)
           (fabs (* (- 1.0 z) (/ x y)))
           (fabs (/ (fma z x (- -4.0 x)) y))))
        double code(double x, double y, double z) {
        	double tmp;
        	if (x <= -8e+72) {
        		tmp = fabs(((1.0 - z) * (x / y)));
        	} else {
        		tmp = fabs((fma(z, x, (-4.0 - x)) / y));
        	}
        	return tmp;
        }
        
        function code(x, y, z)
        	tmp = 0.0
        	if (x <= -8e+72)
        		tmp = abs(Float64(Float64(1.0 - z) * Float64(x / y)));
        	else
        		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y));
        	end
        	return tmp
        end
        
        code[x_, y_, z_] := If[LessEqual[x, -8e+72], N[Abs[N[(N[(1.0 - z), $MachinePrecision] * N[(x / y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq -8 \cdot 10^{+72}:\\
        \;\;\;\;\left|\left(1 - z\right) \cdot \frac{x}{y}\right|\\
        
        \mathbf{else}:\\
        \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < -7.99999999999999955e72

          1. Initial program 91.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left|\color{blue}{\left(1 - z\right)} \cdot \frac{x}{y}\right| \]
            15. lower-/.f6499.9

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

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

          if -7.99999999999999955e72 < x

          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 rewrites98.5%

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

        Alternative 6: 69.5% accurate, 1.4× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left|\frac{x}{y}\right|\\ \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
        (FPCore (x y z)
         :precision binary64
         (let* ((t_0 (fabs (/ x y))))
           (if (<= x -1.55) 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 <= -1.55) {
        		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 <= (-1.55d0)) 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 <= -1.55) {
        		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 <= -1.55:
        		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(x / y))
        	tmp = 0.0
        	if (x <= -1.55)
        		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 <= -1.55)
        		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, -1.55], 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 -1.55:\\
        \;\;\;\;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 < -1.55000000000000004 or 4 < x

          1. Initial program 89.3%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              \[\leadsto \left|\frac{\color{blue}{x - -1 \cdot 4}}{y}\right| \]
            18. metadata-eval62.2

              \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
          5. Applied rewrites62.2%

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

            \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
          7. Step-by-step derivation
            1. Applied rewrites61.6%

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

            if -1.55000000000000004 < x < 4

            1. Initial program 98.9%

              \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
            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-/.f6482.6

                \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
            5. Applied rewrites82.6%

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

          Alternative 7: 70.5% 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 94.0%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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-eval72.7

              \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
          5. Applied rewrites72.7%

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

          Alternative 8: 34.4% accurate, 2.6× speedup?

          \[\begin{array}{l} \\ \left|\frac{x}{y}\right| \end{array} \]
          (FPCore (x y z) :precision binary64 (fabs (/ x y)))
          double code(double x, double y, double z) {
          	return fabs((x / 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 / y))
          end function
          
          public static double code(double x, double y, double z) {
          	return Math.abs((x / y));
          }
          
          def code(x, y, z):
          	return math.fabs((x / y))
          
          function code(x, y, z)
          	return abs(Float64(x / y))
          end
          
          function tmp = code(x, y, z)
          	tmp = abs((x / y));
          end
          
          code[x_, y_, z_] := N[Abs[N[(x / y), $MachinePrecision]], $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left|\frac{x}{y}\right|
          \end{array}
          
          Derivation
          1. Initial program 94.0%

            \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
          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-eval72.7

              \[\leadsto \left|\frac{x - \color{blue}{-4}}{y}\right| \]
          5. Applied rewrites72.7%

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

            \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
          7. Step-by-step derivation
            1. Applied rewrites34.2%

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

            Reproduce

            ?
            herbie shell --seed 2024254 
            (FPCore (x y z)
              :name "fabs fraction 1"
              :precision binary64
              (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))