Average Error: 5.9 → 0.4
Time: 5.0s
Precision: binary64
\[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]
↓
\[\begin{array}{l} \mathbf{if}\;x \leq 3398719.205669345:\\ \;\;\;\;\left(\left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \sqrt[3]{\log x \cdot \left(x - 0.5\right)}\right) - x\right) + 0.91893853320467\right) + \frac{z \cdot \left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) + 0.083333333333333}{x}\\ \mathbf{else}:\\ \;\;\;\;\left(0.91893853320467 + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right)\right) + \left(\left(y + 0.0007936500793651\right) \cdot \left(z \cdot \frac{z}{x}\right) - 0.0027777777777778 \cdot \frac{z}{x}\right)\\ \end{array}\]
\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}
↓
\begin{array}{l}
\mathbf{if}\;x \leq 3398719.205669345:\\
\;\;\;\;\left(\left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \sqrt[3]{\log x \cdot \left(x - 0.5\right)}\right) - x\right) + 0.91893853320467\right) + \frac{z \cdot \left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) + 0.083333333333333}{x}\\

\mathbf{else}:\\
\;\;\;\;\left(0.91893853320467 + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right)\right) + \left(\left(y + 0.0007936500793651\right) \cdot \left(z \cdot \frac{z}{x}\right) - 0.0027777777777778 \cdot \frac{z}{x}\right)\\

\end{array}
(FPCore (x y z)
 :precision binary64
 (+
  (+ (- (* (- x 0.5) (log x)) x) 0.91893853320467)
  (/
   (+
    (* (- (* (+ y 0.0007936500793651) z) 0.0027777777777778) z)
    0.083333333333333)
   x)))
↓
(FPCore (x y z)
 :precision binary64
 (if (<= x 3398719.205669345)
   (+
    (+
     (-
      (*
       (cbrt (* (log x) (- x 0.5)))
       (* (cbrt (* (log x) (- x 0.5))) (cbrt (* (log x) (- x 0.5)))))
      x)
     0.91893853320467)
    (/
     (+
      (* z (- (* (+ y 0.0007936500793651) z) 0.0027777777777778))
      0.083333333333333)
     x))
   (+
    (+
     0.91893853320467
     (+
      (* (- x 0.5) (log (* (cbrt x) (cbrt x))))
      (- (* (- x 0.5) (log (cbrt x))) x)))
    (-
     (* (+ y 0.0007936500793651) (* z (/ z x)))
     (* 0.0027777777777778 (/ z x))))))
double code(double x, double y, double z) {
	return ((double) (((double) (((double) (((double) (((double) (x - 0.5)) * ((double) log(x)))) - x)) + 0.91893853320467)) + (((double) (((double) (((double) (((double) (((double) (y + 0.0007936500793651)) * z)) - 0.0027777777777778)) * z)) + 0.083333333333333)) / x)));
}
↓
double code(double x, double y, double z) {
	double tmp;
	if ((x <= 3398719.205669345)) {
		tmp = ((double) (((double) (((double) (((double) (((double) cbrt(((double) (((double) log(x)) * ((double) (x - 0.5)))))) * ((double) (((double) cbrt(((double) (((double) log(x)) * ((double) (x - 0.5)))))) * ((double) cbrt(((double) (((double) log(x)) * ((double) (x - 0.5)))))))))) - x)) + 0.91893853320467)) + (((double) (((double) (z * ((double) (((double) (((double) (y + 0.0007936500793651)) * z)) - 0.0027777777777778)))) + 0.083333333333333)) / x)));
	} else {
		tmp = ((double) (((double) (0.91893853320467 + ((double) (((double) (((double) (x - 0.5)) * ((double) log(((double) (((double) cbrt(x)) * ((double) cbrt(x)))))))) + ((double) (((double) (((double) (x - 0.5)) * ((double) log(((double) cbrt(x)))))) - x)))))) + ((double) (((double) (((double) (y + 0.0007936500793651)) * ((double) (z * (z / x))))) - ((double) (0.0027777777777778 * (z / x)))))));
	}
	return tmp;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original5.9
Target1.2
Herbie0.4
\[\left(\left(\left(x - 0.5\right) \cdot \log x + \left(0.91893853320467 - x\right)\right) + \frac{0.083333333333333}{x}\right) + \frac{z}{x} \cdot \left(z \cdot \left(y + 0.0007936500793651\right) - 0.0027777777777778\right)\]

Derivation

  1. Split input into 2 regimes

  2. if x < 3398719.20566934487

    1. Initial program Error: 0.2 bits

      \[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]
    2. Using strategy rm

    3. Applied add-cube-cbrtError: 0.2 bits

      \[\leadsto \left(\left(\color{blue}{\left(\sqrt[3]{\left(x - 0.5\right) \cdot \log x} \cdot \sqrt[3]{\left(x - 0.5\right) \cdot \log x}\right) \cdot \sqrt[3]{\left(x - 0.5\right) \cdot \log x}} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    4. SimplifiedError: 0.2 bits

      \[\leadsto \left(\left(\color{blue}{\left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \sqrt[3]{\log x \cdot \left(x - 0.5\right)}\right)} \cdot \sqrt[3]{\left(x - 0.5\right) \cdot \log x} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    5. SimplifiedError: 0.2 bits

      \[\leadsto \left(\left(\left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \sqrt[3]{\log x \cdot \left(x - 0.5\right)}\right) \cdot \color{blue}{\sqrt[3]{\log x \cdot \left(x - 0.5\right)}} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    if 3398719.20566934487 < x

    1. Initial program Error: 10.1 bits

      \[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]
    2. Using strategy rm

    3. Applied add-cube-cbrtError: 10.1 bits

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log \color{blue}{\left(\left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) \cdot \sqrt[3]{x}\right)} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    4. Applied log-prodError: 10.2 bits

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \color{blue}{\left(\log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \log \left(\sqrt[3]{x}\right)\right)} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    5. Applied distribute-lft-inError: 10.2 bits

      \[\leadsto \left(\left(\color{blue}{\left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right)\right)} - x\right) + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    6. Applied associate--l+Error: 10.1 bits

      \[\leadsto \left(\color{blue}{\left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right)} + 0.91893853320467\right) + \frac{\left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) \cdot z + 0.083333333333333}{x}\]

    7. Taylor expanded around inf Error: 10.2 bits

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right) + 0.91893853320467\right) + \color{blue}{\left(\left(0.0007936500793651 \cdot \frac{{z}^{2}}{x} + \frac{{z}^{2} \cdot y}{x}\right) - 0.0027777777777778 \cdot \frac{z}{x}\right)}\]

    8. SimplifiedError: 0.5 bits

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right) + 0.91893853320467\right) + \color{blue}{\left(\left(\frac{z}{x} \cdot z\right) \cdot \left(y + 0.0007936500793651\right) - 0.0027777777777778 \cdot \frac{z}{x}\right)}\]
  3. Recombined 2 regimes into one program.

  4. Final simplificationError: 0.4 bits

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 3398719.205669345:\\ \;\;\;\;\left(\left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \left(\sqrt[3]{\log x \cdot \left(x - 0.5\right)} \cdot \sqrt[3]{\log x \cdot \left(x - 0.5\right)}\right) - x\right) + 0.91893853320467\right) + \frac{z \cdot \left(\left(y + 0.0007936500793651\right) \cdot z - 0.0027777777777778\right) + 0.083333333333333}{x}\\ \mathbf{else}:\\ \;\;\;\;\left(0.91893853320467 + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \left(\left(x - 0.5\right) \cdot \log \left(\sqrt[3]{x}\right) - x\right)\right)\right) + \left(\left(y + 0.0007936500793651\right) \cdot \left(z \cdot \frac{z}{x}\right) - 0.0027777777777778 \cdot \frac{z}{x}\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2020203 
(FPCore (x y z)
  :name "Numeric.SpecFunctions:$slogFactorial from math-functions-0.1.5.2, B"
  :precision binary64

  :herbie-target
  (+ (+ (+ (* (- x 0.5) (log x)) (- 0.91893853320467 x)) (/ 0.083333333333333 x)) (* (/ z x) (- (* z (+ y 0.0007936500793651)) 0.0027777777777778)))

  (+ (+ (- (* (- x 0.5) (log x)) x) 0.91893853320467) (/ (+ (* (- (* (+ y 0.0007936500793651) z) 0.0027777777777778) z) 0.083333333333333) x)))