Abstract
In recent years, there have been significant improvements in algorithms both for Quantified Boolean Formulas (QBF) and for Maximum Satisfiability (MaxSAT). This paper studies an optimization extension of QBF and considers the problem in a quantified MaxSAT setting. More precisely, the general QMaxSAT problem is defined for QBFs with a set of soft clausal constraints and consists in finding the largest subset of the soft constraints such that the remaining QBF is true. Two approaches are investigated. One is based on relaxing the soft clauses and performing an iterative search on the cost function. The other approach, which is the main contribution of the paper, is inspired by recent work on MaxSAT, and exploits the iterative identification of unsatisfiable cores. The paper investigates the application of these approaches to the two concrete problems of computing smallest minimal unsatisfiable subformulas (SMUS) and smallest minimal equivalent subformulas (SMES), decision versions of which are well-known problems in the second level of the polynomial hierarchy. Experimental results, obtained on representative problem instances, indicate that the core-guided approach for the SMUS and SMES problems outperforms the use of iterative search over the values of the cost function. More significantly, the core-guided approach to SMUS also outperforms the state-of-the-art SMUS extractor Digger.
Keywords
Quantified Boolean formula Optimization SAT MaxSAT Smallest MUS/MESPreview
Unable to display preview. Download preview PDF.
References
- 1.Andraus, Z.S., Liffiton, M.H., & Sakallah, K.A. (2006). Refinement strategies for verification methods based on datapath abstraction. In ASP-DAC (pp. 19–24). doi: 10.1145/1118299.1118306.
- 2.Andraus, Z.S., Liffiton, M.H., & Sakallah, K.A. (2008). Reveal: a formal verification tool for verilog designs. In LPAR (pp. 343–352). doi: 10.1007/978-3-540-89439-1_25.
- 3.Ansótegui, C., Bonet, M.L., & Levy, J. (2009). Solving (weighted) partial MaxSAT through satisfiability testing. In SAT (pp. 427–440).Google Scholar
- 4.Ansótegui, C., Bonet, M.L., & Levy, J. (2010). A new algorithm for weighted partial MaxSAT. In AAAI. Google Scholar
- 5.Ansótegui, C., Bonet, M.L., & Levy, J. (2013). SAT-based MaxSAT algorithms. Artificial Intelligence, 196, 77–105.CrossRefMathSciNetzbMATHGoogle Scholar
- 6.Ansotegui, C., Gomes, C.P., & Selman, B. (2005). The Achilles’ heel of QBF. In AAAI (pp. 275–281).Google Scholar
- 7.Bailey, J., & Stuckey, P.J. (2005). Discovery of minimal unsatisfiable subsets of constraints using hitting set dualization. In PADL (pp. 174–186).Google Scholar
- 8.Balabanov, V., & Jiang, J.H.R. (2011). Resolution proofs and Skolem functions in QBF evaluation and applications. In G. Gopalakrishnan, S. Qadeer (Eds.), CAV (pp. 149–164).Google Scholar
- 9.Balabanov, V., & Jiang, J.H.R. (2012). Unified QBF certification and its applications. Formal Methods in System Design, 41(1), 45–65.CrossRefzbMATHGoogle Scholar
- 10.Balabanov, V., Widl, M., & Jiang, J.H.R. (2014). QBF resolution systems and their proof complexities. In C. Sinz, U. Egly (Eds.), SAT (pp. 154–169). Springer.Google Scholar
- 11.Belov, A., Janota, M., Lynce, I., & Marques-Silva, J. (2012). On computing minimal equivalent subformulas. In M. Milano (Ed.), CP (Vol. 7514, pp. 158–174). Springer.Google Scholar
- 12.Belov, A., Janota, M., Lynce, I., & Marques-Silva, J. (2014). Algorithms for computing minimal equivalent subformulas. Artificial Intelligence, 216, 309–326. doi: 10.1016/j.artint.2014.07.011.CrossRefMathSciNetzbMATHGoogle Scholar
- 13.Belov, A., Lynce, I., & Marques-Silva, J. (2012). Towards efficient MUS extraction. AI Communication, 25(2), 97–116.MathSciNetzbMATHGoogle Scholar
- 14.Belov, A., Morgado, A., & Marques-Silva, J. (2013). SAT-based preprocessing for MaxSAT. In LPAR (pp. 96–111). doi: 10.1007/978-3-642-45221-5_7.
- 15.Benedetti, M., Lallouet, A., & Vautard, J. (2008). Quantified constraint optimization. In CP (pp. 463–477).Google Scholar
- 16.Berre, D.L., & Parrain, A. (2010). The Sat4j library, release 2.2. JSAT, 7(2-3), 59–6.Google Scholar
- 17.Birnbaum, E., & Lozinskii, E.L. (2003). Consistent subsets of inconsistent systems: structure and behaviour. Journal of Experimental & Theoretical Artificial Intelligence, 15(1), 25–46.CrossRefzbMATHGoogle Scholar
- 18.Chen, H., Janota, M., & Marques-Silva, J. (2012). QBF-based Boolean function bi-decomposition. In DATE (pp. 816–819).Google Scholar
- 19.Chen, H., & Pál, M. (2004). Optimization, games, and quantified constraint satisfaction. In Mathematical foundations of computer science (pp. 239–250).Google Scholar
- 20.Clarke, E.M., Grumberg, O., Jha, S., Lu, Y., & Veith, H. (2003). Counterexample-guided abstraction refinement for symbolic model checking. Journal of ACM, 50(5), 752–794.CrossRefMathSciNetGoogle Scholar
- 21.Condon, A., Feigenbaum, J., Lund, C., & Shor, P.W. (1995). Probabilistically checkable debate systems and nonapproximability of PSPACE-hard functions. Chicago Journal of Theoretical Computer Science, 1995.Google Scholar
- 22.Eén, N., & Sörensson, N. (2003). An extensible SAT-solver. In SAT (pp. 502–518).Google Scholar
- 23.Egly, U., Lonsing, F., & Widl, M. (2013). Long-distance resolution: Proof generation and strategy extraction in search-based QBF solving. In K. L. McMillan, A. Middeldorp, A. Voronkov (Eds.), LPAR (Vol. 8312, pp. 291–308). Springer.Google Scholar
- 24.Fu, Z., & Malik, S. (2006). On solving the partial MAX-SAT problem. In A. Biere, C. P. Gomes (Eds.), SAT, lecture notes in computer science (Vol. 4121, pp. 252–265). Springer.Google Scholar
- 25.Goldberg, E.I., & Novikov, Y. (2003). Verification of proofs of unsatisfiability for CNF formulas. In DATE (pp. 10,886–10,891). IEEE Computer Society.Google Scholar
- 26.Goultiaeva, A., & Bacchus, F. (2010). Exploiting QBF duality on a circuit representation. AAAI.Google Scholar
- 27.Goultiaeva, A., & Bacchus, F. (2013). Recovering and utilizing partial duality in QBF. In SAT (pp. 83–99). doi: 10.1007/978-3-642-39071-5_8.
- 28.Goultiaeva, A., Seidl, M., & Biere, A. (2013). Bridging the gap between dual propagation and CNF-based QBF solving. In DATE (pp. 811–814).Google Scholar
- 29.Gupta, A. (2006). Learning abstractions for model checking, Ph.D. thesis, Carnegie Mellon University.Google Scholar
- 30.Han, B., & Lee, S.J. (1999). Deriving minimal conflict sets by CS-trees with mark set in diagnosis from first principles. IEEE Transactions on Systems, Man, and Cybernetics: Part B, 29(2), 281–286.CrossRefGoogle Scholar
- 31.Heras, F., Morgado, A., & Marques-Silva, J. (2011). Core-guided binary search algorithms for maximum satisfiability. In W. Burgard, D. Roth (Eds.), AAAI. AAAI Press.Google Scholar
- 32.Heule, M., Seidl, M., & Biere, A. (2014). A unified proof system for QBF preprocessing. In S. Demri, D. Kapur, C. Weidenbach (Eds.), IJCAR (Vol. 8562, pp. 91–106).Google Scholar
- 33.Ignatiev, A., Janota, M., & Marques-Silva, J. (2013). Quantified maximum satisfiability: A core-guided approach. In M. Järvisalo, A. Van Gelder (Eds.), SAT (Vol. 7962, pp. 250–266). Springer.Google Scholar
- 34.Ignatiev, A., Morgado, A., Manquinho, V.M., Lynce, I., & Marques-Silva, J. (2014). Progression in maximum satisfiability. In ECAI (pp. 453–458). doi: 10.3233/978-1-61499-419-0-453.
- 35.Jain, H., Kroening, D., Sharygina, N., & Clarke, E.M. (2005). Word level predicate abstraction and refinement for verifying RTL verilog. In DAC (pp. 445–450). doi: 10.1145/1065579.1065697.
- 36.Janota, M., Grigore, R., & Marques-Silva, J. (2013). On QBF proofs and preprocessing. In K.L. McMillan, A. Middeldorp, A. Voronkov (Eds.), LPAR (Vol. 8312, pp. 473–489). Springer.Google Scholar
- 37.Janota, M., Klieber, W., Marques-Silva, J., & Clarke, E.M. (2012). Solving QBF with counterexample guided refinement. In A. Cimatti, R. Sebastiani (Eds.), SAT (Vol. 7317, pp. 114–128). Springer.Google Scholar
- 38.Janota, M., & Marques-Silva, J. (2011). Abstraction-based algorithm for 2QBF. In SAT (pp. 230–244).Google Scholar
- 39.Kleine Büning, H., & Bubeck, U. (2009). Theory of quantified Boolean formulas. In A. Biere, M. Heule, H. van Maaren, T. Walsh (Eds.), Handbook of satisfiability, frontiers in artificial intelligence and applications (Vol. 185, pp. 735–760). IOS Press.Google Scholar
- 40.Kleine Büning, H., Karpinski, M., & Flögel, A. (1995). Resolution for quantified Boolean formulas. Information and Computation, 117(1), 12–18.CrossRefMathSciNetzbMATHGoogle Scholar
- 41.Kleine Büning, H., Subramani, K., & Zhao, X. (2007). Boolean functions as models for quantified Boolean formulas. Journal of Automated Reasoning, 39(1), 49–75.CrossRefMathSciNetzbMATHGoogle Scholar
- 42.Klieber, W., Sapra, S., Gao, S., & Clarke, E.M. (2010). A non-prenex, non-clausal QBF solver with game-state learning. In SAT (pp. 128–142). doi: 10.1007/978-3-642-14186-7_12.
- 43.Kullmann, O. (2011). Constraint satisfaction problems in clausal form II: minimal unsatisfiability and conflict structure. Fundamental and Information, 109(1), 83–119.MathSciNetzbMATHGoogle Scholar
- 44.Liberatore, P. (2005). Redundancy in logic I: CNF propositional formulae. Artificial Intelligence, 163(2), 203–232.CrossRefMathSciNetzbMATHGoogle Scholar
- 45.Liffiton, M.H., Mneimneh, M.N., Lynce, I., Andraus, Z.S., Marques-Silva, J., & Sakallah, K.A. (2009). A branch and bound algorithm for extracting smallest minimal unsatisfiable subformulas. Constraints, 14(4), 415–442.CrossRefMathSciNetzbMATHGoogle Scholar
- 46.Liffiton, M.H., & Sakallah, K.A. (2005). On finding all minimally unsatisfiable subformulas. In SAT (pp. 173–186).Google Scholar
- 47.Liffiton, M.H., & Sakallah, K.A. (2008). Algorithms for Computing Minimal Unsatisfiable Subsets of Constraints. Journal of Automated Reasoning, 40(1), 1–33.CrossRefMathSciNetzbMATHGoogle Scholar
- 48.Lonsing, F., & Egly, U. (2014). Incremental QBF solving. In CP (pp. 514–530).Google Scholar
- 49.Lynce, I., & Marques-Silva, J.P. (2004). On computing minimum unsatisfiable cores. In SAT.Google Scholar
- 50.Manquinho, V.M., Marques-Silva, J., & Planes, J. (2009). Algorithms for weighted Boolean optimization. In SAT (pp. 495–508).Google Scholar
- 51.Marques-Silva, J. (2010). Minimal unsatisfiability: models, algorithms and applications (invited paper). In ISMVL (pp. 9–14). IEEE Computer Society.Google Scholar
- 52.Marques-Silva, J., Heras, F., Janota, M., Previti, A., & Belov, A. (2013). On computing minimal correction subsets. In IJCAI.Google Scholar
- 53.Mneimneh, M.N., Lynce, I., Andraus, Z.S., Marques-Silva, J.P., & Sakallah, K.A. (2005). A branch-and-bound algorithm for extracting smallest minimal unsatisfiable formulas. In SAT (pp. 467–474).Google Scholar
- 54.Morgado, A., Dodaro, C., & Marques-Silva, J. (2014). Core-guided MaxSAT with soft cardinality constraints. In CP (pp. 564–573). doi: 10.1007/978-3-319-10428-7_41.
- 55.Morgado, A., Heras, F., Liffiton, M.H., Planes, J., & Marques-Silva, J. (2013). Iterative and core-guided MaxSAT solving: a survey and assessment. Constraints, 18 (4), 478–534.CrossRefMathSciNetGoogle Scholar
- 56.Narodytska, N., & Bacchus, F. (2014). Maximum satisfiability using core-guided MaxSAT resolution. In AAAI (pp. 2717–2723).Google Scholar
- 57.Niemetz, A., Preiner, M., Lonsing, F., Seidl, M., & Biere, A. (2012). Resolution-based certificate extraction for QBF - (tool presentation). In A. Cimatti, R. Sebastiani (Eds.), SAT (Vol. 7317, pp. 430–435). Springer.Google Scholar
- 58.Nöhrer, A., Biere, A., & Egyed, A. (2012). Managing SAT inconsistencies with HUMUS. In VAMOS (pp. 83–91).Google Scholar
- 59.Plaisted, D.A., & Greenbaum, S. (1986). A structure-preserving clause form translation. Journal of Symbolic Computation, 2(3), 293–304. doi: 10.1016/S0747-7171(86)80028-1.CrossRefMathSciNetzbMATHGoogle Scholar
- 60.Reimer, S., Sauer, M., Marin, P., & Becker, B. (2014). QBF with soft variables. ECEASST 70.Google Scholar
- 61.Reiter, R. (1987). A theory of diagnosis from first principles. Artificial Intelligence, 32(1), 57–95.CrossRefMathSciNetzbMATHGoogle Scholar
- 62.Roussel, O., & Manquinho, V. (2009). Pseudo-Boolean and cardinality constraints. In A. Biere, M. Heule, H. van Maaren, T. Walsh (Eds.), Handbook of satisfiability, frontiers in artificial intelligence and applications (Vol. 185, pp. 695–733). IOS Press.Google Scholar
- 63.Ryvchin, V., & Strichman, O. (2011). Faster extraction of high-level minimal unsatisfiable cores. In SAT (pp. 174–187).Google Scholar
- 64.Schaefer, M., & Umans, C. (2002). Completeness in the polynomial-time hierarchy: a compendium. SIGACT News, 33(3), 32–49.CrossRefGoogle Scholar
- 65.Sinz, C., Kaiser, A., & Küchlin, W. (2003). Formal methods for the validation of automotive product configuration data. AI EDAM, 17(1), 75–97.Google Scholar
- 66.Stuckey, P.J. (2013). There are no CNF problems. In SAT (pp. 19–21). doi: 10.1007/978-3-642-39071-5_3.
- 67.Stuckey, P.J., Sulzmann, M., & Wazny, J. (2003). Interactive type debugging in Haskell. In ACM SIGPLAN workshop on Haskell (pp. 72–83). ACM.Google Scholar
- 68.Tseitin, G.S. (1968). On the complexity of derivations in the propositional calculus. Studies in Mathematics and Mathematical Logic Part II, 115–125.Google Scholar
- 69.Van Gelder, A. (2012). Contributions to the theory of practical quantified Boolean formula solving. In M. Milano (Ed.), CP (Vol. 7514, pp. 647–663). Springer.Google Scholar
- 70.Yu, Y., & Malik, S. (2005). Validating the result of a quantified Boolean formula (QBF) solver: theory and practice. In ASP-DAC (pp. 1047–1051).Google Scholar
- 71.Zhang, J., Li, S., & Shen, S. (2006). Extracting minimum unsatisfiable cores with a greedy genetic algorithm. In AUS-AI (pp. 847–856).Google Scholar
- 72.Zhang, L. (2006). Solving QBF by combining conjunctive and disjunctive normal forms. In AAAI (pp. 143–150).Google Scholar
- 73.Zhang, L., & Malik, S. (2002). Conflict driven learning in a quantified Boolean satisfiability solver. In ICCAD (pp. 442–449).Google Scholar
- 74.Zhang, L., & Malik, S. (2003). Validating SAT solvers using an independent resolution-based checker: practical implementations and other applications. In DATE (pp. 10,880–10,885). IEEE Computer Society.Google Scholar