Average Error: 0.0 → 0.0
Time: 6.9s
Precision: 64
\[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.9189385332046730026078762421093415468931\]
↓
\[\left(x \cdot \left(y - 1\right) - y \cdot \frac{1}{2}\right) + \frac{8277062471433911}{9007199254740992}\]
\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.9189385332046730026078762421093415468931
↓
\left(x \cdot \left(y - 1\right) - y \cdot \frac{1}{2}\right) + \frac{8277062471433911}{9007199254740992}
double f(double x, double y) {
        double r50845 = x;
        double r50846 = y;
        double r50847 = 1.0;
        double r50848 = r50846 - r50847;
        double r50849 = r50845 * r50848;
        double r50850 = 0.5;
        double r50851 = r50846 * r50850;
        double r50852 = r50849 - r50851;
        double r50853 = 0.918938533204673;
        double r50854 = r50852 + r50853;
        return r50854;
}
↓
double f(double x, double y) {
        double r50855 = x;
        double r50856 = y;
        double r50857 = 1.0;
        double r50858 = r50856 - r50857;
        double r50859 = r50855 * r50858;
        double r50860 = 2.0;
        double r50861 = r50857 / r50860;
        double r50862 = r50856 * r50861;
        double r50863 = r50859 - r50862;
        double r50864 = 8277062471433911.0;
        double r50865 = 9007199254740992.0;
        double r50866 = r50864 / r50865;
        double r50867 = r50863 + r50866;
        return r50867;
}

Error

Bits error versus x

Bits error versus y

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 0.0

    \[\left(x \cdot \left(y - 1\right) - y \cdot 0.5\right) + 0.9189385332046730026078762421093415468931\]

  2. Simplified0.0

    \[\leadsto \color{blue}{\left(x \cdot \left(y - 1\right) - y \cdot \frac{1}{2}\right) + \frac{8277062471433911}{9007199254740992}}\]

  3. Final simplification0.0

    \[\leadsto \left(x \cdot \left(y - 1\right) - y \cdot \frac{1}{2}\right) + \frac{8277062471433911}{9007199254740992}\]

Reproduce

herbie shell --seed 2019303 
(FPCore (x y)
  :name "Numeric.SpecFunctions:logGamma from math-functions-0.1.5.2, A"
  :precision binary64
  (+ (- (* x (- y 1)) (* y 0.5)) 0.918938533204673003))