int user_check_validity_of_cut(void *user, cut_data *new_cut)
This function is provided as a debugging tool. Every cut that is to be sent to the LP solver is first passed to this function where the user can independently verify that the cut is valid by testing it against a known feasible solution (usually an optimal one). This is useful for determining why a particular known feasible (optimal) solution was never found. Usually, this is due to an invalid cut being added. See Section 1.12.4 for more on this feature.