,
Tomáš Peitl
,
Stefan Szeider
,
Hai Xia
Creative Commons Attribution 4.0 International license
Parallel solving via cube-and-conquer is a key method for solving hard instances with SAT. While cube-and-conquer has proven successful for pure SAT problems, notably the Pythagorean triples conjecture, its application to SAT solvers augmented with propagators presents unique challenges as propagators learn constraints dynamically during the search. We study this problem using SAT Modulo Symmetries (SMS) as our primary test case. In our setting, the SMS symmetry-breaking propagator is an ordinary IPASIR-UP propagator; the techniques below do not rely on properties specific to symmetry breaking, except in the benchmark instantiations. Through extensive experimentation comprising over 20,000 CPU hours, we systematically evaluate different cube-and-conquer variants on three well-studied combinatorial problems. Our methodology combines prerun phases to collect learned constraints, various cubing strategies, and parameter tuning via algorithm configuration. The comprehensive empirical evaluation provides new insights into effective cubing strategies for propagator-based SAT solving. Our best method reduces total solving time by factors of 2-10x from improved cubing, and reduces the time for the hardest cubes by factors of 2-50x.
@InProceedings{kirchweger_et_al:LIPIcs.CP.2026.33,
author = {Kirchweger, Markus and Peitl, Tom\'{a}\v{s} and Szeider, Stefan and Xia, Hai},
title = {{Smart Cubing for Graph Search: A Comparative Study}},
booktitle = {32nd International Conference on Principles and Practice of Constraint Programming (CP 2026)},
pages = {33:1--33:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-432-1},
ISSN = {1868-8969},
year = {2026},
volume = {379},
editor = {Beldiceanu, Nicolas},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2026.33},
URN = {urn:nbn:de:0030-drops-266652},
doi = {10.4230/LIPIcs.CP.2026.33},
annote = {Keywords: cube and conquer, graph search, algorithm configuration, SAT solving}
}