\pi \cdot \ell - \frac{1}{F \cdot F} \cdot \tan \left(\pi \cdot \ell\right)\pi \cdot \ell - \frac{\sqrt{1}}{F} \cdot \left(\frac{\sqrt{1}}{\left(1 \cdot \sqrt[3]{F}\right) \cdot \sqrt[3]{F}} \cdot \frac{\tan \left(\pi \cdot \ell\right)}{\sqrt[3]{F}}\right)double f(double F, double l) {
double r20258 = atan2(1.0, 0.0);
double r20259 = l;
double r20260 = r20258 * r20259;
double r20261 = 1.0;
double r20262 = F;
double r20263 = r20262 * r20262;
double r20264 = r20261 / r20263;
double r20265 = tan(r20260);
double r20266 = r20264 * r20265;
double r20267 = r20260 - r20266;
return r20267;
}
double f(double F, double l) {
double r20268 = atan2(1.0, 0.0);
double r20269 = l;
double r20270 = r20268 * r20269;
double r20271 = 1.0;
double r20272 = sqrt(r20271);
double r20273 = F;
double r20274 = r20272 / r20273;
double r20275 = 1.0;
double r20276 = cbrt(r20273);
double r20277 = r20275 * r20276;
double r20278 = r20277 * r20276;
double r20279 = r20272 / r20278;
double r20280 = tan(r20270);
double r20281 = r20280 / r20276;
double r20282 = r20279 * r20281;
double r20283 = r20274 * r20282;
double r20284 = r20270 - r20283;
return r20284;
}



Bits error versus F



Bits error versus l
Results
Initial program 16.8
rmApplied add-sqr-sqrt16.8
Applied times-frac16.8
Applied associate-*l*12.8
rmApplied associate-*l/12.8
rmApplied add-cube-cbrt13.0
Applied times-frac13.0
rmApplied *-un-lft-identity13.0
Final simplification13.0
herbie shell --seed 2019356 +o rules:numerics
(FPCore (F l)
:name "VandenBroeck and Keller, Equation (6)"
:precision binary64
(- (* PI l) (* (/ 1 (* F F)) (tan (* PI l)))))