\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 r62242 = beta;
double r62243 = alpha;
double r62244 = r62242 - r62243;
double r62245 = r62243 + r62242;
double r62246 = 2.0;
double r62247 = r62245 + r62246;
double r62248 = r62244 / r62247;
double r62249 = 1.0;
double r62250 = r62248 + r62249;
double r62251 = r62250 / r62246;
return r62251;
}
double f(double alpha, double beta) {
double r62252 = alpha;
double r62253 = 8092481.162986399;
bool r62254 = r62252 <= r62253;
double r62255 = beta;
double r62256 = r62252 + r62255;
double r62257 = 2.0;
double r62258 = r62256 + r62257;
double r62259 = r62255 / r62258;
double r62260 = r62252 / r62258;
double r62261 = 1.0;
double r62262 = r62260 - r62261;
double r62263 = 3.0;
double r62264 = pow(r62262, r62263);
double r62265 = cbrt(r62264);
double r62266 = r62259 - r62265;
double r62267 = r62266 / r62257;
double r62268 = 4.0;
double r62269 = 2.0;
double r62270 = pow(r62252, r62269);
double r62271 = r62268 / r62270;
double r62272 = 8.0;
double r62273 = pow(r62252, r62263);
double r62274 = r62272 / r62273;
double r62275 = r62271 - r62274;
double r62276 = r62257 / r62252;
double r62277 = r62275 - r62276;
double r62278 = r62259 - r62277;
double r62279 = r62278 / r62257;
double r62280 = r62254 ? r62267 : r62279;
return r62280;
}



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))