orbital branching

Symmetry Presolving for Mixed-Integer Programs: Binary Structure Preservation and Relations to Orbital Branching

Categories Integer Programming Tags , , , ,

This paper investigates a presolving method for handling symmetries in mixed-integer programs, based on inequalities computed from so-called Schreier-Sims tables. We show that an iterative application of this method together with merging variables produces an instance for which the symmetry group is trivial. We then prove that the problem structure can be preserved for certain … Read more

A Computational Comparison of Symmetry Handling Methods for Mixed Integer Programs

Categories (Mixed) Integer Linear Programming Tags , , , ,

The handling of symmetries in mixed integer programs in order to speed up the solution process of branch-and-cut solvers has recently received significant attention, both in theory and practice. This paper compares different methods for handling symmetries using a common implementation framework. We start by investigating the computation of symmetries and analyze the symmetries present … Read more