Average Error: 0.0 → 0.0
Time: 2.1s
Precision: 64
\[\frac{x + 1}{1 - x}\]
↓
\[\log \left(e^{\frac{x + 1}{1 - x}}\right)\]
\frac{x + 1}{1 - x}
↓
\log \left(e^{\frac{x + 1}{1 - x}}\right)
double f(double x) {
        double r59974 = x;
        double r59975 = 1.0;
        double r59976 = r59974 + r59975;
        double r59977 = r59975 - r59974;
        double r59978 = r59976 / r59977;
        return r59978;
}
↓
double f(double x) {
        double r59979 = x;
        double r59980 = 1.0;
        double r59981 = r59979 + r59980;
        double r59982 = r59980 - r59979;
        double r59983 = r59981 / r59982;
        double r59984 = exp(r59983);
        double r59985 = log(r59984);
        return r59985;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 0.0

    \[\frac{x + 1}{1 - x}\]
  2. Using strategy rm

  3. Applied add-log-exp0.0

    \[\leadsto \color{blue}{\log \left(e^{\frac{x + 1}{1 - x}}\right)}\]

  4. Final simplification0.0

    \[\leadsto \log \left(e^{\frac{x + 1}{1 - x}}\right)\]

Reproduce

herbie shell --seed 2020039 
(FPCore (x)
  :name "Prelude:atanh from fay-base-0.20.0.1"
  :precision binary64
  (/ (+ x 1) (- 1 x)))