The presence of symmetries of binary programs typically degrade the performance of branch-and-bound solvers. In this article, we derive efficient variable fixing algorithms to discard symmetric solutions from the search space based on propagation techniques for cyclic groups. Our algorithms come with the guarantee to find all possible variable fixings that can be derived from symmetry arguments, i.e., one cannot find more variable fixings than those found by our algorithms. Since every permutation symmetry group of a binary program has cyclic subgroups, the derived algorithms can be used to handle symmetries in any symmetric binary program. In experiments we also provide numerical evidence that our algorithms handle symmetries more efficiently than other variable fixing algorithms for cyclic symmetries.
Citation
Eindhoven University of Technology, Department of Mathematics and Computer Science, Combinatorial Optimization, P.O. Box 513, 5600 MB Eindhoven, March 2022