Abstract
In answer set programming systems like Smodels and some SAT solvers, constraint propagation is carried out by a mechanism called lookahead. The question arises as what is the pruning power of lookahead, and how such pruning power fares in comparison with the consistency techniques in solving CSPs. In this paper, we study the pruning power of lookahead by relating it to local consistencies under two different encodings from CSPs to answer set programs. This leads to an understanding of how the search space is pruned in an answer set solver with lookahead for solving CSPs. On the other hand, lookahead as a general constraint propagation mechanism provides a uniform algorithm for enforcing a variety of local consistencies. We also study the impact on the search efficiency under these encodings.
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References
Bessière, C.: Uniform random binary csp generator. Website, http://www.lirmm.fr/~bessiere/generator.html (Retrieved December 19, 2004)
Bessière, C., Debruyne, R.: Theoretical analysis of singleton arc consistency. In: Proc. ECAI 2004 Workshop on Modeling and Solving Problems with Constraints, pp. 20–29 (2004)
Bessière, C., Hebrard, E., Walsh, T.: Local consistencies in SAT. In: Giunchiglia, E., Tacchella, A. (eds.) SAT 2003. LNCS, vol. 2919, pp. 299–314. Springer, Heidelberg (2004)
Davis, M., Logemann, G., Loveland, D.: A machine program for theorem proving. Communications of the ACM 5(7), 394–397 (1962)
Debruyne, R., Bessière, C.: Some practical filtering techniques. In: Proc. IJCAI 1997, pp. 412–417 (1997)
Debruyne, R., Bessière, C.: Domain filtering consistencies. J. Artificial Intelligence Research 14, 205–230 (2001)
Elkabani, I., Pontelli, E., Son, T.C.: Smodels with CLP and its applications: a simple and effective approach to aggregates in ASP. In: Demoen, B., Lifschitz, V. (eds.) ICLP 2004. LNCS, vol. 3132, pp. 73–89. Springer, Heidelberg (2004)
Freeman, J.W.: Improvements to propositional satisfiability search algorithms. PhD thesis, Department of Computer and Information Science, University of Pennsylvania (1995)
Gelfond, M., Lifschitz, V.: The stable model semantics for logic programming. In: Proc. 5th ICLP, pp. 1070–1080. MIT Press, Cambridge (1988)
Gent, I.: Arc consistency in SAT. In: Proc. ECAI 2003, pp. 121–125 (2002)
Kasif, S.: On the parallel complexity of discrete relaxation in constraint satisfaction networks. Artificial Intelligence, 275–286 (1990)
Niemelä, I.: Logic programs with stable model semantics as a constraint programming paradigm. Annals of Math. and Artificial Intelligence 25(3-4), 241–273 (1999)
Prosser, P., Stergiou, K., Walsh, T.: Singleton consistencies. In: Dechter, R. (ed.) CP 2000. LNCS, vol. 1894, pp. 353–368. Springer, Heidelberg (2000)
Simons, P.: Extending and Implementing the Stable Model Semantics. PhD thesis, Helsinki University of Technology, Helsinki, Finland (2000)
Walsh, T.: CSP vs. SAT. In: Dechter, R. (ed.) CP 2000. LNCS, vol. 1894, pp. 441–456. Springer, Heidelberg (2000)
You, J., Hou, G.: Arc consistency + unit propagation = lookahead. In: Demoen, B., Lifschitz, V. (eds.) ICLP 2004. LNCS, vol. 3132, pp. 314–328. Springer, Heidelberg (2004)
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You, JH., Liu, G., Yuan, L.Y., Onuczko, C. (2005). Lookahead in Smodels Compared to Local Consistencies in CSP. In: Baral, C., Greco, G., Leone, N., Terracina, G. (eds) Logic Programming and Nonmonotonic Reasoning. LPNMR 2005. Lecture Notes in Computer Science(), vol 3662. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11546207_21
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DOI: https://doi.org/10.1007/11546207_21
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