\pi \cdot \ell - \frac{1}{F \cdot F} \cdot \tan \left(\pi \cdot \ell\right)\pi \cdot \ell - \frac{\sqrt[3]{1} \cdot \sqrt[3]{1}}{F} \cdot \frac{\sqrt[3]{1} \cdot \tan \left(\left(\pi \cdot \left(\sqrt[3]{\ell} \cdot \left(\sqrt[3]{\sqrt[3]{\ell} \cdot \sqrt[3]{\ell}} \cdot \sqrt[3]{\sqrt[3]{\ell}}\right)\right)\right) \cdot \sqrt[3]{\ell}\right)}{F}double f(double F, double l) {
double r20967 = atan2(1.0, 0.0);
double r20968 = l;
double r20969 = r20967 * r20968;
double r20970 = 1.0;
double r20971 = F;
double r20972 = r20971 * r20971;
double r20973 = r20970 / r20972;
double r20974 = tan(r20969);
double r20975 = r20973 * r20974;
double r20976 = r20969 - r20975;
return r20976;
}
double f(double F, double l) {
double r20977 = atan2(1.0, 0.0);
double r20978 = l;
double r20979 = r20977 * r20978;
double r20980 = 1.0;
double r20981 = cbrt(r20980);
double r20982 = r20981 * r20981;
double r20983 = F;
double r20984 = r20982 / r20983;
double r20985 = cbrt(r20978);
double r20986 = r20985 * r20985;
double r20987 = cbrt(r20986);
double r20988 = cbrt(r20985);
double r20989 = r20987 * r20988;
double r20990 = r20985 * r20989;
double r20991 = r20977 * r20990;
double r20992 = r20991 * r20985;
double r20993 = tan(r20992);
double r20994 = r20981 * r20993;
double r20995 = r20994 / r20983;
double r20996 = r20984 * r20995;
double r20997 = r20979 - r20996;
return r20997;
}



Bits error versus F



Bits error versus l
Results
Initial program 16.7
rmApplied add-cube-cbrt16.7
Applied times-frac16.7
Applied associate-*l*12.6
rmApplied associate-*l/12.6
rmApplied add-cube-cbrt12.8
Applied associate-*r*12.8
rmApplied add-cube-cbrt12.8
Applied cbrt-prod12.9
Final simplification12.9
herbie shell --seed 2020001 +o rules:numerics
(FPCore (F l)
:name "VandenBroeck and Keller, Equation (6)"
:precision binary64
(- (* PI l) (* (/ 1 (* F F)) (tan (* PI l)))))