| a_n |
Numerator of first value |
| a_d |
Denominator of first value |
| b_n |
Numerator of second value |
| b_d |
Denominator of second value |
| res_n |
Pointer to int to hold the result numerator |
| res_d |
Pointer to int to hold the result denominator |
false on overflow, true otherwise. |