\pi \cdot \ell - \frac{1}{F \cdot F} \cdot \tan \left(\pi \cdot \ell\right)\pi \cdot \ell - \left(\tan \left(\sqrt{\pi} \cdot \left(\ell \cdot \left(\sqrt{\sqrt{\pi}} \cdot \sqrt{\sqrt{\pi}}\right)\right)\right) \cdot \frac{\sqrt{1}}{F}\right) \cdot \frac{\sqrt{1}}{F}double f(double F, double l) {
double r946358 = atan2(1.0, 0.0);
double r946359 = l;
double r946360 = r946358 * r946359;
double r946361 = 1.0;
double r946362 = F;
double r946363 = r946362 * r946362;
double r946364 = r946361 / r946363;
double r946365 = tan(r946360);
double r946366 = r946364 * r946365;
double r946367 = r946360 - r946366;
return r946367;
}
double f(double F, double l) {
double r946368 = atan2(1.0, 0.0);
double r946369 = l;
double r946370 = r946368 * r946369;
double r946371 = sqrt(r946368);
double r946372 = sqrt(r946371);
double r946373 = r946372 * r946372;
double r946374 = r946369 * r946373;
double r946375 = r946371 * r946374;
double r946376 = tan(r946375);
double r946377 = 1.0;
double r946378 = sqrt(r946377);
double r946379 = F;
double r946380 = r946378 / r946379;
double r946381 = r946376 * r946380;
double r946382 = r946381 * r946380;
double r946383 = r946370 - r946382;
return r946383;
}



Bits error versus F



Bits error versus l
Results
Initial program 16.6
rmApplied add-sqr-sqrt16.6
Applied times-frac16.6
Applied associate-*l*12.4
rmApplied add-sqr-sqrt12.5
Applied associate-*l*12.5
rmApplied add-sqr-sqrt12.5
Applied sqrt-prod12.4
Final simplification12.4
herbie shell --seed 2019172 +o rules:numerics
(FPCore (F l)
:name "VandenBroeck and Keller, Equation (6)"
(- (* PI l) (* (/ 1.0 (* F F)) (tan (* PI l)))))