Lightweight Dynamic Symmetry Breaking

LDSB is a dynamic symmetry breaking method and, therefore, does not interfere with the given search heuristic. Like the shortcut SBDS method, it might trade completeness for efficiency, and it does not require complex group theory computations. Like the GAP-SBDS method, it only requires the user to provide the symmetries, and pruning of symmetric parts of the search tree occurs as early as it is useful. Importantly, the overhead introduced by LDSB to exploit symmetries is very small, since it targets those that can be represented and checked efficiently. An implementation of LDSB is described. Results are so promising that we believe LDSB can be used as a default search method even when looking only for the first solution.