\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\begin{array}{l}
\mathbf{if}\;\alpha \le 1290203807327944437661696:\\
\;\;\;\;\frac{e^{\log \left(\frac{\beta}{\left(\alpha + \beta\right) + 2} - \left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)\right)}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{\beta}{\left(\alpha + \beta\right) + 2} - \left(\left(\frac{\frac{4}{\alpha}}{\alpha} + \frac{-8}{{\alpha}^{3}}\right) + \frac{-2}{\alpha}\right)}{2}\\
\end{array}double f(double alpha, double beta) {
double r163857 = beta;
double r163858 = alpha;
double r163859 = r163857 - r163858;
double r163860 = r163858 + r163857;
double r163861 = 2.0;
double r163862 = r163860 + r163861;
double r163863 = r163859 / r163862;
double r163864 = 1.0;
double r163865 = r163863 + r163864;
double r163866 = r163865 / r163861;
return r163866;
}
double f(double alpha, double beta) {
double r163867 = alpha;
double r163868 = 1.2902038073279444e+24;
bool r163869 = r163867 <= r163868;
double r163870 = beta;
double r163871 = r163867 + r163870;
double r163872 = 2.0;
double r163873 = r163871 + r163872;
double r163874 = r163870 / r163873;
double r163875 = r163867 / r163873;
double r163876 = 1.0;
double r163877 = r163875 - r163876;
double r163878 = r163874 - r163877;
double r163879 = log(r163878);
double r163880 = exp(r163879);
double r163881 = r163880 / r163872;
double r163882 = 4.0;
double r163883 = r163882 / r163867;
double r163884 = r163883 / r163867;
double r163885 = 8.0;
double r163886 = -r163885;
double r163887 = 3.0;
double r163888 = pow(r163867, r163887);
double r163889 = r163886 / r163888;
double r163890 = r163884 + r163889;
double r163891 = -r163872;
double r163892 = r163891 / r163867;
double r163893 = r163890 + r163892;
double r163894 = r163874 - r163893;
double r163895 = r163894 / r163872;
double r163896 = r163869 ? r163881 : r163895;
return r163896;
}



Bits error versus alpha



Bits error versus beta
Results
if alpha < 1.2902038073279444e+24Initial program 0.7
rmApplied div-sub0.7
Applied associate-+l-0.7
rmApplied add-exp-log0.7
if 1.2902038073279444e+24 < alpha Initial program 50.1
rmApplied div-sub50.1
Applied associate-+l-48.6
Taylor expanded around inf 17.8
Simplified17.8
Final simplification5.9
herbie shell --seed 2020001
(FPCore (alpha beta)
:name "Octave 3.8, jcobi/1"
:precision binary64
:pre (and (> alpha -1) (> beta -1))
(/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2)) 1) 2))