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Trade-offs Between Time and Memory in a Tighter Model of CDCL SAT Solvers

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Theory and Applications of Satisfiability Testing – SAT 2016 (SAT 2016)

Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 9710))

Abstract

A long line of research has studied the power of conflict-driven clause learning (CDCL) and how it compares to the resolution proof system in which it searches for proofs. It has been shown that CDCL can polynomially simulate resolution even with an adversarially chosen learning scheme as long as it is asserting. However, the simulation only works under the assumption that no learned clauses are ever forgotten, and the polynomial blow-up is significant. Moreover, the simulation requires very frequent restarts, whereas the power of CDCL with less frequent or entirely without restarts remains poorly understood. With a view towards obtaining results with tighter relations between CDCL and resolution, we introduce a more fine-grained model of CDCL that captures not only time but also memory usage and number of restarts. We show how previously established strong size-space trade-offs for resolution can be transformed into equally strong trade-offs between time and memory usage for CDCL, where the upper bounds hold for CDCL without any restarts using the standard 1UIP clause learning scheme, and the (in some cases tightly matching) lower bounds hold for arbitrarily frequent restarts and arbitrary clause learning schemes.

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Notes

  1. 1.

    We mention for completeness that there is also a total space measure counting the number of literals in memory, which has been studied in, e.g., [1, 13, 15, 16], but for our purposes clause space seems like a more relevant measure to focus on.

  2. 2.

    In fact, our results hold for any UIP scheme, but for simplicity we focus on 1UIP, which is anyway dominant in practice.

References

  1. Alekhnovich, M., Ben-Sasson, E., Razborov, A.A., Wigderson, A.: Space complexity in propositional calculus. SIAM J. Comput. 31(4), 1184–1211 (2002). Preliminary version in STOC 2000

    Article  MathSciNet  MATH  Google Scholar 

  2. Alekhnovich, M., Razborov, A.A.: Resolution is not automatizable unless W[P] is tractable. SIAM J. Comput. 38(4), 1347–1363 (2008). Preliminary version in FOCS 2001

    Article  MathSciNet  MATH  Google Scholar 

  3. Atserias, A., Fichte, J.K., Thurley, M.: Clause-learning algorithms with many restarts and bounded-width resolution. J. Artif. Intell. Res. 40, 353–373 (2011). Preliminary version in SAT 2009

    MathSciNet  MATH  Google Scholar 

  4. Audemard, G., Simon, L.: Predicting learnt clauses quality in modern SAT solvers. In: Proceedings of the 21st International Joint Conference on Artificial Intelligence (IJCAI 2009), pp. 399–404, July 2009

    Google Scholar 

  5. Bayardo Jr., R.J., Schrag, R.: Using CSP look-back techniques to solve real-world SAT instances. In: Proceedings of the 14th National Conference on Artificial Intelligence (AAAI 1997), pp. 203–208, July 1997

    Google Scholar 

  6. Beame, P., Beck, C., Impagliazzo, R.: Time-space tradeoffs in resolution: superpolynomial lower bounds for superlinear space. In: Proceedings of the 44th Annual ACM Symposium on Theory of Computing (STOC 2012), pp. 213–232, May 2012

    Google Scholar 

  7. Beame, P., Kautz, H., Sabharwal, A.: Towards understanding and harnessing the potential of clause learning. J. Artif. Intell. Res. 22, 319–351 (2004). Preliminary version in IJCAI 2003

    MathSciNet  MATH  Google Scholar 

  8. Beame, P., Sabharwal, A.: Non-restarting SAT solvers with simple preprocessing can efficiently simulate resolution. In: Proceedings of the 28th National Conference on Artificial Intelligence (AAAI 2014), pp. 2608–2615. AAAI Press, July 2014

    Google Scholar 

  9. Beck, C., Nordström, J., Tang, B.: Some trade-off results for polynomial calculus. In: Proceedings of the 45th Annual ACM Symposium on Theory of Computing (STOC 2013), pp. 813–822, May 2013

    Google Scholar 

  10. Ben-Sasson, E., Galesi, N.: Space complexity of random formulae in resolution. Random Struct. Algorithms 23(1), 92–109 (2003). Preliminary version in CCC 2001

    Article  MathSciNet  MATH  Google Scholar 

  11. Ben-Sasson, E., Nordström, J.: Understanding space in proof complexity: separations and trade-offs via substitutions. In: Proceedings of the 2nd Symposium on Innovations in Computer Science (ICS 2011). pp. 401–416, January 2011

    Google Scholar 

  12. Ben-Sasson, E., Wigderson, A.: Short proofs are narrow–resolution madesimple. J. ACM 48(2), 149–169 (2001). Preliminary version in STOC 1999

    Article  MathSciNet  MATH  Google Scholar 

  13. Bennett, P., Bonacina, I., Galesi, N., Huynh, T., Molloy, M., Wollan, P.: Space proof complexity for random 3-CNFs. Technical report arXiv.org:1503.01613, April 2015

  14. Blake, A.: Canonical Expressions in Boolean Algebra. Ph.D. thesis, University of Chicago (1937)

    Google Scholar 

  15. Bonacina, I.: Total space in resolution is at least width squared. In: Proceedings of the 43rd International Colloquium on Automata, Languages and Programming (ICALP 2016), (to appear, July 2016)

    Google Scholar 

  16. Bonacina, I., Galesi, N., Thapen, N.: Total space in resolution. In: Proceedings of the 55th Annual IEEE Symposium on Foundations of Computer Science (FOCS 2014), pp. 641–650, October 2014

    Google Scholar 

  17. Bonet, M.L., Buss, S., Johannsen, J.: Improved separations of regular resolution from clause learning proof systems. J. Artif. Intell. Res. 49, 669–703 (2014)

    MathSciNet  MATH  Google Scholar 

  18. Buss, S.R., Hoffmann, J., Johannsen, J.: Resolution trees with lemmas: resolution refinements that characterize DLL-algorithms with clause learning. Logical Meth. Comput. Sci. 4(4:13), 1–28 (2008)

    MathSciNet  MATH  Google Scholar 

  19. Buss, S.R., Kołodziejczyk, L.: Small stone in pool. Logical Meth. Comput. Sci. 10, 1–22 (2014)

    MathSciNet  MATH  Google Scholar 

  20. Chvátal, V., Szemerédi, E.: Many hard examples for resolution. J. ACM 35(4), 759–768 (1988)

    Article  MathSciNet  MATH  Google Scholar 

  21. Cook, S.A., Reckhow, R.: The relative efficiency of propositional proof systems. J. Symbolic Logic 44(1), 36–50 (1979)

    Article  MathSciNet  MATH  Google Scholar 

  22. Davis, M., Logemann, G., Loveland, D.: A machine program for theorem proving. Commun. ACM 5(7), 394–397 (1962)

    Article  MathSciNet  MATH  Google Scholar 

  23. Davis, M., Putnam, H.: A computing procedure for quantification theory. J. ACM 7(3), 201–215 (1960)

    Article  MathSciNet  MATH  Google Scholar 

  24. Esteban, J.L., Torán, J.: Space bounds for resolution. Inf. Comput. 171(1), 84–97 (2001). Preliminary versions of these results appeared in STACS 1999 and CSL 1999

    Article  MathSciNet  MATH  Google Scholar 

  25. Haken, A.: The intractability of resolution. Theor. Comput. Sci. 39(2–3), 297–308 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  26. Hertel, P., Bacchus, F., Pitassi, T., Van Gelder, A.: Clause learning can effectively P-simulate general propositional resolution. In: Proceedings of the 23rd National Conference on Artificial Intelligence (AAAI 2008), pp. 283–290, July 2008

    Google Scholar 

  27. Marques-Silva, J.P., Sakallah, K.A.: GRASP: a search algorithm for propositional satisfiability. IEEE Trans. Comput. 48(5), 506–521 (1999). Preliminary version in ICCAD 1996

    Article  MathSciNet  Google Scholar 

  28. 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, June 2001

    Google Scholar 

  29. Nieuwenhuis, R., Oliveras, A., Tinelli, C.: Solving SAT and SAT modulo theories: from an abstract Davis-Putnam-Logemann-Loveland procedure to DPLL(T). J. ACM 53(6), 937–977 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  30. Pipatsrisawat, K., Darwiche, A.: On the power of clause-learning SAT solvers as resolution engines. Artif. Intell. 175, 512–525 (2011). Preliminary version in CP 2009

    Article  MathSciNet  MATH  Google Scholar 

  31. Urquhart, A.: Hard examples for resolution. J. ACM 34(1), 209–219 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  32. Van Gelder, A.: Pool resolution and its relation to regular resolution and DPLL with clause learning. In: Sutcliffe, G., Voronkov, A. (eds.) LPAR 2005. LNCS (LNAI), vol. 3835, pp. 580–594. Springer, Heidelberg (2005)

    Chapter  Google Scholar 

  33. Zhang, L., Madigan, C.F., Moskewicz, M.W., Malik, S.: Efficient conflict driven learning in boolean satisfiability solver. In: Proceedings of the IEEE/ACM International Conference on Computer-Aided Design (ICCAD 2001), pp. 279–285, November 2001

    Google Scholar 

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Acknowledgements

We are grateful to the anonymous SAT conference reviewers for detailed comments that helped improve the exposition in this paper.

The third author performed this work while at KTH Royal Institute of Technology, and most of the work of the second and fourth author was done while visiting KTH. The first, third, fifth, and sixth author were funded by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013) / ERC grant agreement no. 279611 as well as by Swedish Research Council grant 621-2012-5645. The third author was also supported by the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme/ERC grant agreement no. 648276.

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Elffers, J., Johannsen, J., Lauria, M., Magnard, T., Nordström, J., Vinyals, M. (2016). Trade-offs Between Time and Memory in a Tighter Model of CDCL SAT Solvers. In: Creignou, N., Le Berre, D. (eds) Theory and Applications of Satisfiability Testing – SAT 2016. SAT 2016. Lecture Notes in Computer Science(), vol 9710. Springer, Cham. https://doi.org/10.1007/978-3-319-40970-2_11

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  • DOI: https://doi.org/10.1007/978-3-319-40970-2_11

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