New Hybrid Heuristics for Pseudo-Boolean Propagation
Mia Müßig, Jan Johannsen
TL;DR
The paper tackles the efficiency of unit propagation in pseudo-Boolean solving by refining the hybrid counting-watched-literal method. It introduces two heuristics, Absolute Hybrid and Additive Hybrid, that decide when to use counting versus watching based on coefficient magnitudes, and demonstrates substantial runtime improvements on PB competition datasets, especially for knapsack-like instances. The changes require minimal code modifications, suggesting easy integration and potential automatic tuning based on instance characteristics. Overall, the work advances practical performance of PB solvers by targeted heuristic tuning of the propagation mechanism.
Abstract
In pseudo-boolean solving the currently most successful unit propagation strategy is a hybrid mode combining the watched literal scheme with the counting method. This short paper introduces new heuristics for this hybrid decision, which are able to drastically outperform the current method in the RoundingSAT solver.
