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Conflict-driven ASP solving with external sources


Answer Set Programming (ASP) is a well-known problem solving approach based on nonmonotonic logic programs and efficient solvers. To enable access to external information, hex-programs extend programs with external atoms, which allow for a bidirectional communication between the logic program and external sources of computation (e.g., description logic reasoners and Web resources). Current solvers evaluate hex-programs by a translation to ASP itself, in which values of external atoms are guessed and verified after the ordinary answer set computation. This elegant approach does not scale with the number of external accesses in general, in particular in presence of nondeterminism (which is instrumental for ASP). In this paper, we present a novel, native algorithm for evaluating hex-programs which uses learning techniques. In particular, we extend conflict-driven ASP solving techniques, which prevent the solver from running into the same conflict again, from ordinary to hex-programs. We show how to gain additional knowledge from external source evaluations and how to use it in a conflict-driven algorithm. We first target the uninformed case, i.e., when we have no extra information on external sources, and then extend our approach to the case where additional meta-information is available. Experiments show that learning from external sources can significantly decrease both the runtime and the number of considered candidate compatible sets.

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Brewka, G. and Eiter, T. 2007. Equilibria in heterogeneous nonmonotonic multi-context systems. In AAAI'07. AAAI Press, 385390.
Brewka, G., Eiter, T. and Truszczyński, M. 2011. Answer set programming at a glance. Commun. ACM 54, 12, 92103.
Biere, A., Heule, M. J. H., van Maaren, H. and Walsh, T., Eds. 2009. Handbook of Satisfiability. Frontiers in Artificial Intelligence and Applications, vol. 185. IOS Press.
Dao-Tran, M., Eiter, T. and Krennwallner, T. 2009. Realizing default logic over description logic knowledge bases. In ECSQARU'09. Springer, 602613.
Drescher, C., Gebser, M., Grote, T., Kaufmann, B., König, A., Ostrowski, M. and Schaub, T. 2008. Conflict-driven disjunctive answer set solving. In KR'08. AAAI Press, 422432.
Eiter, T., Fink, M., Ianni, G., Krennwallner, T. and Schüller, P. 2011. Pushing efficient evaluation of HEX programs by modular decomposition. In LPNMR'11. Springer, 93106.
Eiter, T., Fink, M., Schüller, P. and Weinzierl, A. 2010. Finding explanations of inconsistency in multi-context systems. In KR'10. AAAI Press, 329339.
Eiter, T., Ianni, G., Krennwallner, T. and Schindlauer, R. 2008. Exploiting conjunctive queries in description logic programs. Annals of Mathematics and Artificial Intelligence 53, 1–4, 115152.
Eiter, T., Ianni, G., Lukasiewicz, T., Schindlauer, R. and Tompits, H. 2008. Combining answer set programming with description logics for the semantic web. Artificial Intelligence 172, 12-13, 14951539.
Eiter, T., Ianni, G., Schindlauer, R. and Tompits, H. 2005. A uniform integration of higher-order reasoning and external evaluations in answer-set programming. In IJCAI'05. Professional Book Center, 9096.
Eiter, T., Ianni, G., Schindlauer, R. and Tompits, H. 2006. Effective integration of declarative rules with external evaluations for semantic-web reasoning. In ESWC'06. Springer, 273287.
Faber, W., Leone, N. and Pfeifer, G. 2011. Semantics and complexity of recursive aggregates in answer set programming. Artificial Intelligence 175, 1, 278298.
Fages, F. 1994. Consistency of clark's completion and existence of stable models. J. Meth. Logic Comp. Sci. 1, 5160.
Gebser, M., Kaufmann, B., Kaminski, R., Ostrowski, M., Schaub, T. and Schneider, M. T. 2011. Potassco: The Potsdam answer set solving collection. AI Communications 24, 2, 107124.
Gebser, M., Kaufmann, B. and Schaub, T. 2012. Conflict-driven answer set solving: From theory to practice. Artificial Intelligence 187-188, 5289.
Gebser, M., Ostrowski, M. and Schaub, T. 2009. Constraint answer set solving. In ICLP'09. Springer, 235249.
Gelfond, M. and Lifschitz, V. 1991. Classical negation in logic programs and disjunctive databases. New Generat. Comput. 9, 3–4, 365386.
Giunchiglia, E., Lierler, Y. and Maratea, M. 2006. Answer set programming based on propositional satisfiability. Journal of Automated Reasoning 36, 4, 345377.
Goldberg, E. and Novikov, Y. 2007. BerkMin: A fast and robust SAT-solver. Discrete Applied Mathematics 155, 12, 15491561.
Leone, N., Pfeifer, G., Faber, W., Eiter, T., Gottlob, G., Perri, S. and Scarcello, F. 2006. The DLV system for knowledge representation and reasoning. ACM Transactions on Computer Logic 7, 3, 499562.
Lifschitz, V. 2002. Answer set programming and plan generation. Artificial Intelligence 138, 3954.
Lin, F. and Zhao, Y. 2004. ASSAT: computing answer sets of a logic program by SAT solvers. Artificial Intelligence 157, 1–2, 115137.
Marek, V. W. and Truszczyński, M. 1999. Stable models and an alternative logic programming paradigm. In The Logic Programming Paradigm. Springer, 375398.
Motik, B. and Sattler, U. 2006. A comparison of reasoning techniques for querying large description logic ABoxes. In LPAR'06. Springer, 227241.
Niemelä, I. 1999. Logic Programming with Stable Model Semantics as Constraint Programming Paradigm. Annals of Mathematics and Artificial Intelligence 25, 3–4, 241273.
Ostrowski, M. and Schaub, T. 2012. ASP modulo CSP: The clingcon system. Theor. Pract. Log. Prog., Special Issue 28th Intl. Conf. Logic Programming. To appear.
Simons, P., Niemelä, I. and Soininen, T. 2002. Extending and implementing the stable model semantics. Artificial Intelligence 138, 1-2, 181234.
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Theory and Practice of Logic Programming
  • ISSN: 1471-0684
  • EISSN: 1475-3081
  • URL: /core/journals/theory-and-practice-of-logic-programming
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