Average Error: 6.1 → 4.3
Time: 26.0s
Precision: 64
\[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
\[\begin{array}{l} \mathbf{if}\;z \le -1.212196197003972240184625072772756177456 \cdot 10^{45} \lor \neg \left(z \le 0.5108993033454987120478563156211748719215\right):\\ \;\;\;\;\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \left(\frac{{z}^{2}}{x} \cdot \left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) - 0.002777777777777800001512975569539776188321 \cdot \frac{z}{x}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt{x}\right) - x\right) + 0.9189385332046700050057097541866824030876\right)\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\\ \end{array}\]
\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}
\begin{array}{l}
\mathbf{if}\;z \le -1.212196197003972240184625072772756177456 \cdot 10^{45} \lor \neg \left(z \le 0.5108993033454987120478563156211748719215\right):\\
\;\;\;\;\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \left(\frac{{z}^{2}}{x} \cdot \left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) - 0.002777777777777800001512975569539776188321 \cdot \frac{z}{x}\right)\\

\mathbf{else}:\\
\;\;\;\;\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt{x}\right) - x\right) + 0.9189385332046700050057097541866824030876\right)\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\\

\end{array}
double f(double x, double y, double z) {
        double r353516 = x;
        double r353517 = 0.5;
        double r353518 = r353516 - r353517;
        double r353519 = log(r353516);
        double r353520 = r353518 * r353519;
        double r353521 = r353520 - r353516;
        double r353522 = 0.91893853320467;
        double r353523 = r353521 + r353522;
        double r353524 = y;
        double r353525 = 0.0007936500793651;
        double r353526 = r353524 + r353525;
        double r353527 = z;
        double r353528 = r353526 * r353527;
        double r353529 = 0.0027777777777778;
        double r353530 = r353528 - r353529;
        double r353531 = r353530 * r353527;
        double r353532 = 0.083333333333333;
        double r353533 = r353531 + r353532;
        double r353534 = r353533 / r353516;
        double r353535 = r353523 + r353534;
        return r353535;
}

double f(double x, double y, double z) {
        double r353536 = z;
        double r353537 = -1.2121961970039722e+45;
        bool r353538 = r353536 <= r353537;
        double r353539 = 0.5108993033454987;
        bool r353540 = r353536 <= r353539;
        double r353541 = !r353540;
        bool r353542 = r353538 || r353541;
        double r353543 = x;
        double r353544 = 0.5;
        double r353545 = r353543 - r353544;
        double r353546 = log(r353543);
        double r353547 = r353545 * r353546;
        double r353548 = r353547 - r353543;
        double r353549 = 0.91893853320467;
        double r353550 = r353548 + r353549;
        double r353551 = 2.0;
        double r353552 = pow(r353536, r353551);
        double r353553 = r353552 / r353543;
        double r353554 = y;
        double r353555 = 0.0007936500793651;
        double r353556 = r353554 + r353555;
        double r353557 = r353553 * r353556;
        double r353558 = 0.0027777777777778;
        double r353559 = r353536 / r353543;
        double r353560 = r353558 * r353559;
        double r353561 = r353557 - r353560;
        double r353562 = r353550 + r353561;
        double r353563 = sqrt(r353543);
        double r353564 = log(r353563);
        double r353565 = r353564 * r353545;
        double r353566 = r353545 * r353564;
        double r353567 = r353566 - r353543;
        double r353568 = r353567 + r353549;
        double r353569 = r353565 + r353568;
        double r353570 = r353556 * r353536;
        double r353571 = r353570 - r353558;
        double r353572 = r353571 * r353536;
        double r353573 = 0.083333333333333;
        double r353574 = r353572 + r353573;
        double r353575 = r353574 / r353543;
        double r353576 = r353569 + r353575;
        double r353577 = r353542 ? r353562 : r353576;
        return r353577;
}

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

Original6.1
Target1.2
Herbie4.3
\[\left(\left(\left(x - 0.5\right) \cdot \log x + \left(0.9189385332046700050057097541866824030876 - x\right)\right) + \frac{0.08333333333333299564049667651488562114537}{x}\right) + \frac{z}{x} \cdot \left(z \cdot \left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) - 0.002777777777777800001512975569539776188321\right)\]

Derivation

  1. Split input into 2 regimes
  2. if z < -1.2121961970039722e+45 or 0.5108993033454987 < z

    1. Initial program 23.8

      \[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    2. Taylor expanded around inf 24.5

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \color{blue}{\left(\left(7.936500793651000149400709382518925849581 \cdot 10^{-4} \cdot \frac{{z}^{2}}{x} + \frac{{z}^{2} \cdot y}{x}\right) - 0.002777777777777800001512975569539776188321 \cdot \frac{z}{x}\right)}\]
    3. Simplified16.6

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \color{blue}{\left(\frac{{z}^{2}}{x} \cdot \left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) - 0.002777777777777800001512975569539776188321 \cdot \frac{z}{x}\right)}\]

    if -1.2121961970039722e+45 < z < 0.5108993033454987

    1. Initial program 0.4

      \[\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    2. Using strategy rm
    3. Applied add-sqr-sqrt0.4

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \log \color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right)} - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    4. Applied log-prod0.4

      \[\leadsto \left(\left(\left(x - 0.5\right) \cdot \color{blue}{\left(\log \left(\sqrt{x}\right) + \log \left(\sqrt{x}\right)\right)} - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    5. Applied distribute-rgt-in0.4

      \[\leadsto \left(\left(\color{blue}{\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right)\right)} - x\right) + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    6. Applied associate--l+0.4

      \[\leadsto \left(\color{blue}{\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) - x\right)\right)} + 0.9189385332046700050057097541866824030876\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    7. Applied associate-+l+0.4

      \[\leadsto \color{blue}{\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \left(\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) - x\right) + 0.9189385332046700050057097541866824030876\right)\right)} + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
    8. Simplified0.4

      \[\leadsto \left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \color{blue}{\left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt{x}\right) - x\right) + 0.9189385332046700050057097541866824030876\right)}\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification4.3

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \le -1.212196197003972240184625072772756177456 \cdot 10^{45} \lor \neg \left(z \le 0.5108993033454987120478563156211748719215\right):\\ \;\;\;\;\left(\left(\left(x - 0.5\right) \cdot \log x - x\right) + 0.9189385332046700050057097541866824030876\right) + \left(\frac{{z}^{2}}{x} \cdot \left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) - 0.002777777777777800001512975569539776188321 \cdot \frac{z}{x}\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log \left(\sqrt{x}\right) \cdot \left(x - 0.5\right) + \left(\left(\left(x - 0.5\right) \cdot \log \left(\sqrt{x}\right) - x\right) + 0.9189385332046700050057097541866824030876\right)\right) + \frac{\left(\left(y + 7.936500793651000149400709382518925849581 \cdot 10^{-4}\right) \cdot z - 0.002777777777777800001512975569539776188321\right) \cdot z + 0.08333333333333299564049667651488562114537}{x}\\ \end{array}\]

Reproduce

herbie shell --seed 2019322 
(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)))