\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\begin{array}{l}
\mathbf{if}\;\alpha \le 8092481.162986398674547672271728515625:\\
\;\;\;\;\frac{\frac{\beta}{\left(\alpha + \beta\right) + 2} - \sqrt[3]{{\left(\frac{\alpha}{\left(\alpha + \beta\right) + 2} - 1\right)}^{3}}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{\beta}{\left(\alpha + \beta\right) + 2} - \left(\left(\frac{4}{{\alpha}^{2}} - \frac{8}{{\alpha}^{3}}\right) - \frac{2}{\alpha}\right)}{2}\\
\end{array}double f(double alpha, double beta) {
double r59627 = beta;
double r59628 = alpha;
double r59629 = r59627 - r59628;
double r59630 = r59628 + r59627;
double r59631 = 2.0;
double r59632 = r59630 + r59631;
double r59633 = r59629 / r59632;
double r59634 = 1.0;
double r59635 = r59633 + r59634;
double r59636 = r59635 / r59631;
return r59636;
}
double f(double alpha, double beta) {
double r59637 = alpha;
double r59638 = 8092481.162986399;
bool r59639 = r59637 <= r59638;
double r59640 = beta;
double r59641 = r59637 + r59640;
double r59642 = 2.0;
double r59643 = r59641 + r59642;
double r59644 = r59640 / r59643;
double r59645 = r59637 / r59643;
double r59646 = 1.0;
double r59647 = r59645 - r59646;
double r59648 = 3.0;
double r59649 = pow(r59647, r59648);
double r59650 = cbrt(r59649);
double r59651 = r59644 - r59650;
double r59652 = r59651 / r59642;
double r59653 = 4.0;
double r59654 = 2.0;
double r59655 = pow(r59637, r59654);
double r59656 = r59653 / r59655;
double r59657 = 8.0;
double r59658 = pow(r59637, r59648);
double r59659 = r59657 / r59658;
double r59660 = r59656 - r59659;
double r59661 = r59642 / r59637;
double r59662 = r59660 - r59661;
double r59663 = r59644 - r59662;
double r59664 = r59663 / r59642;
double r59665 = r59639 ? r59652 : r59664;
return r59665;
}



Bits error versus alpha



Bits error versus beta
Results
if alpha < 8092481.162986399Initial program 0.1
rmApplied div-sub0.1
Applied associate-+l-0.1
rmApplied add-cbrt-cube0.1
Simplified0.1
if 8092481.162986399 < alpha Initial program 50.0
rmApplied div-sub49.9
Applied associate-+l-48.3
rmApplied add-cbrt-cube48.3
Simplified48.3
Taylor expanded around inf 18.4
Simplified18.4
Final simplification6.1
herbie shell --seed 2019323
(FPCore (alpha beta)
:name "Octave 3.8, jcobi/1"
:precision binary64
:pre (and (> alpha -1) (> beta -1))
(/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2)) 1) 2))