\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}\begin{array}{l}
\mathbf{if}\;\beta \le 8.4856429570103299 \cdot 10^{177}:\\
\;\;\;\;\frac{\frac{-\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{-\left(\left(\alpha + \beta\right) + 2 \cdot 1\right)}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}double f(double alpha, double beta) {
double r522464 = alpha;
double r522465 = beta;
double r522466 = r522464 + r522465;
double r522467 = r522465 * r522464;
double r522468 = r522466 + r522467;
double r522469 = 1.0;
double r522470 = r522468 + r522469;
double r522471 = 2.0;
double r522472 = r522471 * r522469;
double r522473 = r522466 + r522472;
double r522474 = r522470 / r522473;
double r522475 = r522474 / r522473;
double r522476 = r522473 + r522469;
double r522477 = r522475 / r522476;
return r522477;
}
double f(double alpha, double beta) {
double r522478 = beta;
double r522479 = 8.48564295701033e+177;
bool r522480 = r522478 <= r522479;
double r522481 = alpha;
double r522482 = r522481 + r522478;
double r522483 = r522478 * r522481;
double r522484 = r522482 + r522483;
double r522485 = 1.0;
double r522486 = r522484 + r522485;
double r522487 = 2.0;
double r522488 = r522487 * r522485;
double r522489 = r522482 + r522488;
double r522490 = r522486 / r522489;
double r522491 = -r522490;
double r522492 = -r522489;
double r522493 = r522491 / r522492;
double r522494 = r522489 + r522485;
double r522495 = r522493 / r522494;
double r522496 = 0.0;
double r522497 = r522480 ? r522495 : r522496;
return r522497;
}



Bits error versus alpha



Bits error versus beta
Results
if beta < 8.48564295701033e+177Initial program 1.6
rmApplied frac-2neg1.6
if 8.48564295701033e+177 < beta Initial program 16.3
rmApplied frac-2neg16.3
Taylor expanded around inf 6.4
Final simplification2.3
herbie shell --seed 2020047
(FPCore (alpha beta)
:name "Octave 3.8, jcobi/3"
:precision binary64
:pre (and (> alpha -1) (> beta -1))
(/ (/ (/ (+ (+ (+ alpha beta) (* beta alpha)) 1) (+ (+ alpha beta) (* 2 1))) (+ (+ alpha beta) (* 2 1))) (+ (+ (+ alpha beta) (* 2 1)) 1)))