\frac{-\left(f + n\right)}{f - n}\frac{-1}{\frac{\frac{f}{f + n} \cdot \frac{f}{f + n} - \frac{n}{f + n} \cdot \frac{n}{f + n}}{\frac{f}{f + n} + \frac{n}{f + n}}}double code(double f, double n) {
return (-(f + n) / (f - n));
}
double code(double f, double n) {
return (-1.0 / ((((f / (f + n)) * (f / (f + n))) - ((n / (f + n)) * (n / (f + n)))) / ((f / (f + n)) + (n / (f + n)))));
}



Bits error versus f



Bits error versus n
Results
Initial program 0.0
rmApplied neg-mul-10.0
Applied associate-/l*0.0
rmApplied div-sub0.0
rmApplied flip--0.0
Final simplification0.0
herbie shell --seed 2020075
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))