# Obtaining the system of irredundant inequalities from a set of inequalities using CPLEX

Given a linear system of inequalities $$Ax \geq b$$, I would ideally like to compute the irredundant set for those set of inequalities. I know how to do so mathematically, but I was wondering if there is a function implemented in CPLEX which the user can access and obtain the required irredundant set. When solving a LP using CPLEX, the solver seems to eliminate redundant inequalities as the first step, so I am wondering if it is possible for the user to access the pruned set (even if it is not the irredundant set). If it is possible, can someone please tell me how.

• Gurobi can do what you are asking.
– ktnr
Nov 11 '20 at 7:46
• I guess, if you really want to have an irredundant set for sure, then you will have to do it yourself. As far as I know, presolving does not guarantee irredundancy in any common solver. That being said, CPLEX is also able to write the presolved model (how to do so is depending on the API).
– T_O
Nov 11 '20 at 13:33