\frac{x}{x + 1} - \frac{x + 1}{x - 1}\begin{array}{l}
\mathbf{if}\;x \le -13212.25074346146:\\
\;\;\;\;-3 \cdot \frac{\frac{\frac{1}{x}}{x}}{x} - \left(\frac{3}{x} + \frac{\frac{1}{x}}{x}\right)\\
\mathbf{elif}\;x \le 9551.679161702108:\\
\;\;\;\;\frac{\frac{x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1}}}{\sqrt[3]{x + 1}} - \frac{x + 1}{x - 1}\\
\mathbf{else}:\\
\;\;\;\;-3 \cdot \frac{\frac{\frac{1}{x}}{x}}{x} - \left(\frac{3}{x} + \frac{\frac{1}{x}}{x}\right)\\
\end{array}double f(double x) {
double r2214082 = x;
double r2214083 = 1.0;
double r2214084 = r2214082 + r2214083;
double r2214085 = r2214082 / r2214084;
double r2214086 = r2214082 - r2214083;
double r2214087 = r2214084 / r2214086;
double r2214088 = r2214085 - r2214087;
return r2214088;
}
double f(double x) {
double r2214089 = x;
double r2214090 = -13212.25074346146;
bool r2214091 = r2214089 <= r2214090;
double r2214092 = -3.0;
double r2214093 = 1.0;
double r2214094 = r2214093 / r2214089;
double r2214095 = r2214094 / r2214089;
double r2214096 = r2214095 / r2214089;
double r2214097 = r2214092 * r2214096;
double r2214098 = 3.0;
double r2214099 = r2214098 / r2214089;
double r2214100 = r2214099 + r2214095;
double r2214101 = r2214097 - r2214100;
double r2214102 = 9551.679161702108;
bool r2214103 = r2214089 <= r2214102;
double r2214104 = r2214089 + r2214093;
double r2214105 = cbrt(r2214104);
double r2214106 = r2214105 * r2214105;
double r2214107 = r2214089 / r2214106;
double r2214108 = r2214107 / r2214105;
double r2214109 = r2214089 - r2214093;
double r2214110 = r2214104 / r2214109;
double r2214111 = r2214108 - r2214110;
double r2214112 = r2214103 ? r2214111 : r2214101;
double r2214113 = r2214091 ? r2214101 : r2214112;
return r2214113;
}



Bits error versus x
Results
if x < -13212.25074346146 or 9551.679161702108 < x Initial program 59.4
rmApplied add-cube-cbrt60.2
Applied associate-/r*60.2
Taylor expanded around inf 0.3
Simplified0.0
if -13212.25074346146 < x < 9551.679161702108Initial program 0.1
rmApplied add-cube-cbrt0.1
Applied associate-/r*0.1
Final simplification0.1
herbie shell --seed 2019128
(FPCore (x)
:name "Asymptote C"
(- (/ x (+ x 1)) (/ (+ x 1) (- x 1))))