\pi \cdot \ell - \frac{1}{F \cdot F} \cdot \tan \left(\pi \cdot \ell\right)\begin{array}{l}
\mathbf{if}\;\pi \cdot \ell \le -9.718573105215283439369659162476488255481 \cdot 10^{155}:\\
\;\;\;\;\pi \cdot \ell - \frac{\sqrt{1}}{F} \cdot \left(\frac{\sqrt{1}}{F} \cdot \tan \left(\sqrt{\pi} \cdot \left(\sqrt{\pi} \cdot \ell\right)\right)\right)\\
\mathbf{elif}\;\pi \cdot \ell \le 8.939014277543762652462397904252204810382 \cdot 10^{150}:\\
\;\;\;\;\pi \cdot \ell - \frac{\sqrt{1}}{F} \cdot \frac{\sqrt{1} \cdot \sin \left(\pi \cdot \ell\right)}{F \cdot \left(\left(\frac{1}{24} \cdot \left({\pi}^{4} \cdot {\ell}^{4}\right) + 1\right) - \frac{1}{2} \cdot \left({\pi}^{2} \cdot {\ell}^{2}\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\pi \cdot \ell - \frac{\sqrt{1}}{F} \cdot \frac{\sqrt{1} \cdot \sin \left(\pi \cdot \ell\right)}{F \cdot \cos \left(\left(\left(\sqrt[3]{\sqrt{\pi}} \cdot \sqrt[3]{\sqrt{\pi}}\right) \cdot \left(\sqrt[3]{\sqrt{\pi}} \cdot \sqrt[3]{\sqrt{\pi}}\right)\right) \cdot \left(\sqrt[3]{\pi} \cdot \ell\right)\right)}\\
\end{array}double f(double F, double l) {
double r14745 = atan2(1.0, 0.0);
double r14746 = l;
double r14747 = r14745 * r14746;
double r14748 = 1.0;
double r14749 = F;
double r14750 = r14749 * r14749;
double r14751 = r14748 / r14750;
double r14752 = tan(r14747);
double r14753 = r14751 * r14752;
double r14754 = r14747 - r14753;
return r14754;
}
double f(double F, double l) {
double r14755 = atan2(1.0, 0.0);
double r14756 = l;
double r14757 = r14755 * r14756;
double r14758 = -9.718573105215283e+155;
bool r14759 = r14757 <= r14758;
double r14760 = 1.0;
double r14761 = sqrt(r14760);
double r14762 = F;
double r14763 = r14761 / r14762;
double r14764 = sqrt(r14755);
double r14765 = r14764 * r14756;
double r14766 = r14764 * r14765;
double r14767 = tan(r14766);
double r14768 = r14763 * r14767;
double r14769 = r14763 * r14768;
double r14770 = r14757 - r14769;
double r14771 = 8.939014277543763e+150;
bool r14772 = r14757 <= r14771;
double r14773 = sin(r14757);
double r14774 = r14761 * r14773;
double r14775 = 0.041666666666666664;
double r14776 = 4.0;
double r14777 = pow(r14755, r14776);
double r14778 = pow(r14756, r14776);
double r14779 = r14777 * r14778;
double r14780 = r14775 * r14779;
double r14781 = 1.0;
double r14782 = r14780 + r14781;
double r14783 = 0.5;
double r14784 = 2.0;
double r14785 = pow(r14755, r14784);
double r14786 = pow(r14756, r14784);
double r14787 = r14785 * r14786;
double r14788 = r14783 * r14787;
double r14789 = r14782 - r14788;
double r14790 = r14762 * r14789;
double r14791 = r14774 / r14790;
double r14792 = r14763 * r14791;
double r14793 = r14757 - r14792;
double r14794 = cbrt(r14764);
double r14795 = r14794 * r14794;
double r14796 = r14795 * r14795;
double r14797 = cbrt(r14755);
double r14798 = r14797 * r14756;
double r14799 = r14796 * r14798;
double r14800 = cos(r14799);
double r14801 = r14762 * r14800;
double r14802 = r14774 / r14801;
double r14803 = r14763 * r14802;
double r14804 = r14757 - r14803;
double r14805 = r14772 ? r14793 : r14804;
double r14806 = r14759 ? r14770 : r14805;
return r14806;
}



Bits error versus F



Bits error versus l
Results
if (* PI l) < -9.718573105215283e+155Initial program 21.5
rmApplied add-sqr-sqrt21.5
Applied times-frac21.5
Applied associate-*l*21.5
rmApplied add-sqr-sqrt21.5
Applied associate-*l*21.6
if -9.718573105215283e+155 < (* PI l) < 8.939014277543763e+150Initial program 15.8
rmApplied add-sqr-sqrt15.8
Applied times-frac15.8
Applied associate-*l*9.8
rmApplied tan-quot9.8
Applied frac-times9.7
Taylor expanded around 0 3.9
if 8.939014277543763e+150 < (* PI l) Initial program 21.5
rmApplied add-sqr-sqrt21.5
Applied times-frac21.5
Applied associate-*l*21.5
rmApplied tan-quot21.5
Applied frac-times21.5
rmApplied add-cube-cbrt21.4
Applied associate-*l*21.4
rmApplied add-sqr-sqrt21.5
Applied cbrt-prod21.4
Applied add-sqr-sqrt21.4
Applied cbrt-prod21.4
Applied swap-sqr21.4
Final simplification8.5
herbie shell --seed 2019362
(FPCore (F l)
:name "VandenBroeck and Keller, Equation (6)"
:precision binary64
(- (* PI l) (* (/ 1 (* F F)) (tan (* PI l)))))