\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} + 1}{2}\begin{array}{l}
\mathbf{if}\;\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2} \le -1:\\
\;\;\;\;\frac{\left(2 \cdot \frac{1}{\alpha} + 8 \cdot \frac{1}{{\alpha}^{3}}\right) - 4 \cdot \frac{1}{{\alpha}^{2}}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt[3]{{\left(\left(\alpha + \beta\right) \cdot \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2}\right)}^{3}} + 1}{2}\\
\end{array}double f(double alpha, double beta, double i) {
double r108100 = alpha;
double r108101 = beta;
double r108102 = r108100 + r108101;
double r108103 = r108101 - r108100;
double r108104 = r108102 * r108103;
double r108105 = 2.0;
double r108106 = i;
double r108107 = r108105 * r108106;
double r108108 = r108102 + r108107;
double r108109 = r108104 / r108108;
double r108110 = r108108 + r108105;
double r108111 = r108109 / r108110;
double r108112 = 1.0;
double r108113 = r108111 + r108112;
double r108114 = r108113 / r108105;
return r108114;
}
double f(double alpha, double beta, double i) {
double r108115 = alpha;
double r108116 = beta;
double r108117 = r108115 + r108116;
double r108118 = r108116 - r108115;
double r108119 = r108117 * r108118;
double r108120 = 2.0;
double r108121 = i;
double r108122 = r108120 * r108121;
double r108123 = r108117 + r108122;
double r108124 = r108119 / r108123;
double r108125 = r108123 + r108120;
double r108126 = r108124 / r108125;
double r108127 = -1.0;
bool r108128 = r108126 <= r108127;
double r108129 = 1.0;
double r108130 = r108129 / r108115;
double r108131 = r108120 * r108130;
double r108132 = 8.0;
double r108133 = 3.0;
double r108134 = pow(r108115, r108133);
double r108135 = r108129 / r108134;
double r108136 = r108132 * r108135;
double r108137 = r108131 + r108136;
double r108138 = 4.0;
double r108139 = 2.0;
double r108140 = pow(r108115, r108139);
double r108141 = r108129 / r108140;
double r108142 = r108138 * r108141;
double r108143 = r108137 - r108142;
double r108144 = r108143 / r108120;
double r108145 = r108118 / r108123;
double r108146 = r108145 / r108125;
double r108147 = r108117 * r108146;
double r108148 = pow(r108147, r108133);
double r108149 = cbrt(r108148);
double r108150 = 1.0;
double r108151 = r108149 + r108150;
double r108152 = r108151 / r108120;
double r108153 = r108128 ? r108144 : r108152;
return r108153;
}



Bits error versus alpha



Bits error versus beta



Bits error versus i
Results
if (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i))) (+ (+ (+ alpha beta) (* 2.0 i)) 2.0)) < -1.0Initial program 63.3
Taylor expanded around inf 33.4
if -1.0 < (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2.0 i))) (+ (+ (+ alpha beta) (* 2.0 i)) 2.0)) Initial program 11.9
rmApplied *-un-lft-identity11.9
Applied *-un-lft-identity11.9
Applied times-frac0.5
Applied times-frac0.5
Simplified0.5
rmApplied add-cbrt-cube11.0
Applied add-cbrt-cube16.3
Applied add-cbrt-cube22.4
Applied cbrt-undiv22.4
Applied cbrt-undiv22.4
Applied add-cbrt-cube22.4
Applied cbrt-unprod22.4
Simplified0.5
Final simplification7.8
herbie shell --seed 2020047
(FPCore (alpha beta i)
:name "Octave 3.8, jcobi/2"
:precision binary64
:pre (and (> alpha -1) (> beta -1) (> i 0.0))
(/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2 i))) (+ (+ (+ alpha beta) (* 2 i)) 2)) 1) 2))