\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 r946384 = atan2(1.0, 0.0);
double r946385 = l;
double r946386 = r946384 * r946385;
double r946387 = 1.0;
double r946388 = F;
double r946389 = r946388 * r946388;
double r946390 = r946387 / r946389;
double r946391 = tan(r946386);
double r946392 = r946390 * r946391;
double r946393 = r946386 - r946392;
return r946393;
}
double f(double F, double l) {
double r946394 = atan2(1.0, 0.0);
double r946395 = l;
double r946396 = r946394 * r946395;
double r946397 = sqrt(r946394);
double r946398 = sqrt(r946397);
double r946399 = r946398 * r946398;
double r946400 = r946395 * r946399;
double r946401 = r946397 * r946400;
double r946402 = tan(r946401);
double r946403 = 1.0;
double r946404 = sqrt(r946403);
double r946405 = F;
double r946406 = r946404 / r946405;
double r946407 = r946402 * r946406;
double r946408 = r946407 * r946406;
double r946409 = r946396 - r946408;
return r946409;
}



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)))))