separation

MIR Closures of Polyhedral Sets

  • Sanjeeb Dash
  • Oktay Gunluk
  • Andrea Lodi
    • Categories Cutting Plane Approaches Tags , ,

    We study the mixed-integer rounding (MIR) closures of polyhedral sets. The MIR closure of a polyhedral set is equal to its split closure and the associated separation problem is NP-hard. We describe a mixed-integer programming (MIP) model with linear constraints and a non-linear objective for separating an arbitrary point from the MIR closure of a … Read more

    Two step MIR inequalities for mixed-integer programs

  • Sanjeeb Dash
  • Oktay Gunluk
  • Marcos Goycoolea
    • Categories Cutting Plane Approaches Tags , ,

    Two-step mixed-integer rounding inequalities are valid inequalities derived from a facet of a simple mixed-integer set with three variables and one constraint. In this paper we investigate how to effectively use these inequalities as cutting planes for general mixed-integer problems. We study the separation problem for single constraint sets and show that it can be … Read more