\log \left(x + \sqrt{x \cdot x - 1}\right)\log \left(x + \sqrt{x - 1} \cdot \left(\sqrt{\sqrt{1 + x}} \cdot \sqrt{\sqrt{1 + x}}\right)\right)double f(double x) {
double r2091469 = x;
double r2091470 = r2091469 * r2091469;
double r2091471 = 1.0;
double r2091472 = r2091470 - r2091471;
double r2091473 = sqrt(r2091472);
double r2091474 = r2091469 + r2091473;
double r2091475 = log(r2091474);
return r2091475;
}
double f(double x) {
double r2091476 = x;
double r2091477 = 1.0;
double r2091478 = r2091476 - r2091477;
double r2091479 = sqrt(r2091478);
double r2091480 = r2091477 + r2091476;
double r2091481 = sqrt(r2091480);
double r2091482 = sqrt(r2091481);
double r2091483 = r2091482 * r2091482;
double r2091484 = r2091479 * r2091483;
double r2091485 = r2091476 + r2091484;
double r2091486 = log(r2091485);
return r2091486;
}



Bits error versus x
Results
Initial program 31.4
rmApplied *-un-lft-identity31.4
Applied difference-of-squares31.4
Applied sqrt-prod0.1
rmApplied add-sqr-sqrt0.1
Applied sqrt-prod0.1
Final simplification0.1
herbie shell --seed 2019163
(FPCore (x)
:name "Hyperbolic arc-cosine"
(log (+ x (sqrt (- (* x x) 1)))))