Use the --timeout flag to change the timeout.
\frac{-\left(f + n\right)}{f - n}double f(double f, double n) {
double r53399859 = f;
double r53399860 = n;
double r53399861 = r53399859 + r53399860;
double r53399862 = -r53399861;
double r53399863 = r53399859 - r53399860;
double r53399864 = r53399862 / r53399863;
return r53399864;
}
herbie shell --seed 2019120
(FPCore (f n)
:name "subtraction fraction"
(/ (- (+ f n)) (- f n)))