\frac{x + 1}{1 - x}\frac{1}{\frac{1 - x}{1 + x}}(FPCore (x) :precision binary64 (/ (+ x 1.0) (- 1.0 x)))
(FPCore (x) :precision binary64 (/ 1.0 (/ (- 1.0 x) (+ 1.0 x))))
double code(double x) {
return (x + 1.0) / (1.0 - x);
}
double code(double x) {
return 1.0 / ((1.0 - x) / (1.0 + x));
}



Bits error versus x
Results
Initial program 0.0
rmApplied clear-num_binary640.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2021110
(FPCore (x)
:name "Prelude:atanh from fay-base-0.20.0.1"
:precision binary64
(/ (+ x 1.0) (- 1.0 x)))