Abstract
Modern SAT solvers are based on a paradigm named conflict driven clause learning (CDCL), while local search is an important alternative. Although there have been attempts combining these two methods, this work proposes deeper cooperation techniques. First, we relax the CDCL framework by extending promising branches to complete assignments and calling a local search solver to search for a model nearby. More importantly, the local search assignments and the conflict frequency of variables in local search are exploited in the phase selection and branching heuristics of CDCL. We use our techniques to improve three typical CDCL solvers (glucose, MapleLCMDistChronoBT and Kissat). Experiments on benchmarks from the Main tracks of SAT Competitions 2017–2020 and a real world benchmark of spectrum allocation show that the techniques bring significant improvements, particularly on satisfiable instances. For example, the integration of our techniques allow the three CDCL solvers to solve 62, 67 and 10 more instances in the benchmark of SAT Competition 2020. A resulting solver won the Main Track SAT category in SAT Competition 2020 and also performs very well on the spectrum allocation benchmark. As far as we know, this is the first work that meets the standard of the challenge “Demonstrate the successful combination of stochastic search and systematic search techniques, by the creation of a new algorithm that outperforms the best previous examples of both approaches.” [35] on standard application benchmarks.
S. Cai and X. Zhang—The authors are considered to have equal contributions. Cai contributes mostly on the ideas and partly on the implementations and writes the paper, while Zhang contributes mostly on the implementations and partly on the ideas.
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References
Anbulagan, Pham, D.N., Slaney, J.K., Sattar, A.: Old resolution meets modern SLS. In: Proceedings of AAAI 2005, pp. 354–359 (2005)
Audemard, G., Lagniez, J., Mazure, B., Sais, L.: Integrating conflict driven clause learning to local search. In: Proceedings of LSCS 2009, pp. 55–68 (2009)
Audemard, G., Lagniez, J.-M., Mazure, B., Saïs, L.: Boosting local search thanks to cdcl. In: Fermüller, C.G., Voronkov, A. (eds.) LPAR 2010. LNCS, vol. 6397, pp. 474–488. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-16242-8_34
Audemard, G., Simon, L.: Predicting learnt clauses quality in modern SAT solvers. In: Proceedings of IJCAI 2009, pp. 399–404 (2009)
Balint, A., Henn, M., Gableske, O.: A novel approach to combine a SLS- and a DPLL-solver for the satisfiability problem. In: Kullmann, O. (ed.) SAT 2009. LNCS, vol. 5584, pp. 284–297. Springer, Heidelberg (2009). https://doi.org/10.1007/978-3-642-02777-2_28
Balint, A., Manthey, N.: SparrowToRiss 2018. In: Proceedings of SAT Competition 2018: Solver and Benchmark Descriptions, pp. 38–39 (2018)
Biere, A.: Adaptive restart strategies for conflict driven SAT solvers. In: Kleine Büning, H., Zhao, X. (eds.) SAT 2008. LNCS, vol. 4996, pp. 28–33. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-79719-7_4
Biere, A.: Pre, icosat@sc’09. In: SAT 2009 Competitive Event Booklet, pp. 42–43 (2009)
Biere, A.: Yet another local search solver and lingeling and friends entering the sat competition 2014. Sat Competition 2014(2), 65 (2014)
Biere, A., Fazekas, K., Fleury, M., Heisinger, M.: CaDiCaL, Paracooba, Plingeling and Treengeling entering the SAT Competition, Kissat, pp. 51–53 (2020)
Cai, S., Luo, C., Su, K.: CCAnr+glucose in SAT Competition 2014. In: Proceedings of SAT Competition 2014: Solver and Benchmark Descriptions, p. 17 (2014)
Cai, S., Luo, C., Su, K.: CCAnr: a configuration checking based local search solver for non-random satisfiability. In: Proceedings of SAT 2015, pp. 1–8 (2015)
Cha, B., Iwama, K.: Adding new clauses for faster local search. In: Proceedings of AAAI, vol. 96, pp. 332–337 (1996)
Davis, M., Logemann, G., Loveland, D.W.: A machine program for theorem-proving. Commun. ACM 5(7), 394–397 (1962)
Eén, N., Sörensson, N.: An extensible SAT-solver. In: Giunchiglia, E., Tacchella, A. (eds.) SAT 2003. LNCS, vol. 2919, pp. 502–518. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-24605-3_37
Gershman, R., Strichman, O.: Haifasat: a new robust SAT solver. In: Ur, S., Bin, E., Wolfsthal, Y. (eds.) Proceedings of Haifa Verification Conference 2005, pp. 76–89 (2005)
Goldberg, E.I., Novikov, Y.: Berkmin: a fast and robust sat-solver. In: Proceedings of DATE (2002), pp. 142–149 (2002)
Gomes, C.P., Selman, B., Kautz, H.A.: Boosting combinatorial search through randomization. In: Proceedings of AAAI/IAAI 1998, pp. 431–437 (1998)
Habet, D., Li, C.M., Devendeville, L., Vasquez, M.: A hybrid approach for SAT. In: Proceedings of CP 2002, pp. 172–184 (2002)
Heule, M.J.H., Kullmann, O., Marek, V.W.: Solving and verifying the boolean pythagorean triples problem via cube-and-conquer. In: Creignou, N., Le Berre, D. (eds.) SAT 2016. LNCS, vol. 9710, pp. 228–245. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-40970-2_15
Kautz, H.A., Selman, B.: Planning as satisfiability. In: Proceedings of ECAI 1992, pp. 359–363 (1992)
Kochemazov, S., Zaikin, O., Kondratiev, V., Semenov, A.: Maplelcmdistchronobt-dl, duplicate learnts heuristic-aided solvers at the sat race 2019. In: Proceedings of SAT Race, pp. 24–24 (2019)
Kroc, L., Sabharwal, A., Gomes, C.P., Selman, B.: Integrating systematic and local search paradigms: a new strategy for maxsat. In: Proceedings of IJCAI 2009, pp. 544–551 (2009)
Letombe, F., Marques-Silva, J.: Improvements to hybrid incremental SAT algorithms. In: Kleine Büning, H., Zhao, X. (eds.) SAT 2008. LNCS, vol. 4996, pp. 168–181. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-79719-7_17
Li, C.M., Habet, D.: Description of RSeq2014. In: Proceedings of SAT Competition 2014: Solver and Benchmark Descriptions, p. 72 (2014)
Li, C.M., Li, Yu.: Satisfying versus falsifying in local search for satisfiability. In: Cimatti, A., Sebastiani, R. (eds.) SAT 2012. LNCS, vol. 7317, pp. 477–478. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-31612-8_43
Liang, J.H., Ganesh, V., Poupart, P., Czarnecki, K.: Learning rate based branching heuristic for SAT solvers. In: Creignou, N., Le Berre, D. (eds.) SAT 2016. LNCS, vol. 9710, pp. 123–140. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-40970-2_9
Lorenz, J.-H., Wörz, F.: On the effect of learned clauses on stochastic local search. In: Pulina, L., Seidl, M. (eds.) SAT 2020. LNCS, vol. 12178, pp. 89–106. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-51825-7_7
Luo, M., Li, C., Xiao, F., Manyà, F., Lü, Z.: An effective learnt clause minimization approach for CDCL SAT solvers. In: Proceedings of IJCAI 2017, pp. 703–711 (2017)
Mazure, B., Sais, L., Grégoire, É.: Boosting complete techniques thanks to local search methods. Ann. Math. Artif. Intell. 22(3–4), 319–331 (1998)
Moskewicz, M.W., Madigan, C.F., Zhao, Y., Zhang, L., Malik, S.: Chaff: engineering an efficient SAT solver. In: Proceedings of the 38th Design Automation Conference, DAC 2001, pp. 530–535 (2001)
Newman, N., Fréchette, A., Leyton-Brown, K.: Deep optimization for spectrum repacking. Commun. ACM 61(1), 97–104 (2018)
Oh, C.: Between SAT and UNSAT: the fundamental difference in CDCL SAT. In: Heule, M., Weaver, S. (eds.) SAT 2015. LNCS, vol. 9340, pp. 307–323. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-24318-4_23
Pipatsrisawat, K., Darwiche, A.: A lightweight component caching scheme for satisfiability solvers. In: Marques-Silva, J., Sakallah, K.A. (eds.) SAT 2007. LNCS, vol. 4501, pp. 294–299. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-72788-0_28
Selman, B., Kautz, H.A., McAllester, D.A.: Ten challenges in propositional reasoning and search. In: Proceedings of IJCAI, vol. 97, pp. 50–54 (1997)
Silva, J.P.M., Sakallah, K.A.: GRASP - a new search algorithm for satisfiability. In: Proceedings of ICCAD 1996, pp. 220–227 (1996)
Silva, J.P.M., Sakallah, K.A.: Boolean satisfiability in electronic design automation. In: Proceedings of the DAC 2000, pp. 675–680 (2000)
Acknowledgement
This work is supported by Beijing Academy of Artificial Intelligence (BAAI), and Youth Innovation Promotion Association, Chinese Academy of Sciences [No. 2017150].
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Cai, S., Zhang, X. (2021). Deep Cooperation of CDCL and Local Search for SAT. In: Li, CM., Manyà, F. (eds) Theory and Applications of Satisfiability Testing – SAT 2021. SAT 2021. Lecture Notes in Computer Science(), vol 12831. Springer, Cham. https://doi.org/10.1007/978-3-030-80223-3_6
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