\frac{1}{x + 1} - \frac{1}{x - 1}\frac{\frac{-2}{1 + x}}{x - 1}double f(double x) {
double r5990435 = 1.0;
double r5990436 = x;
double r5990437 = r5990436 + r5990435;
double r5990438 = r5990435 / r5990437;
double r5990439 = r5990436 - r5990435;
double r5990440 = r5990435 / r5990439;
double r5990441 = r5990438 - r5990440;
return r5990441;
}
double f(double x) {
double r5990442 = 2.0;
double r5990443 = -r5990442;
double r5990444 = 1.0;
double r5990445 = x;
double r5990446 = r5990444 + r5990445;
double r5990447 = r5990443 / r5990446;
double r5990448 = r5990445 - r5990444;
double r5990449 = r5990447 / r5990448;
return r5990449;
}



Bits error versus x
Results
Initial program 14.4
rmApplied frac-sub13.8
Taylor expanded around 0 0.4
rmApplied associate-/r*0.1
Final simplification0.1
herbie shell --seed 2019171
(FPCore (x)
:name "Asymptote A"
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))