Average Error: 0.0 → 0.0
Time: 2.3s
Precision: binary64
\[\frac{x + 1}{1 - x} \]
↓
\[\frac{-1 - x}{x + -1} \]
\frac{x + 1}{1 - x}
↓
\frac{-1 - x}{x + -1}

(FPCore (x) :precision binary64 (/ (+ x 1.0) (- 1.0 x)))
↓
(FPCore (x) :precision binary64 (/ (- -1.0 x) (+ x -1.0)))
double code(double x) {
	return (x + 1.0) / (1.0 - x);
}
↓
double code(double x) {
	return (-1.0 - x) / (x + -1.0);
}

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 frac-2neg_binary640.0

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

  4. Final simplification0.0

    \[\leadsto \frac{-1 - x}{x + -1} \]

Reproduce

herbie shell --seed 2021190 
(FPCore (x)
  :name "Prelude:atanh from fay-base-0.20.0.1"
  :precision binary64
  (/ (+ x 1.0) (- 1.0 x)))