The DLV System for Knowledge Representation and Reasoning (2002)

by N Leone, G Pfeifer, W Faber, T Eiter, G Gottlob, C Koch, C Mateis, S Perri, F Scarcello
Venue:Institut für Informationssysteme, Technische Universität Wien, A-1040
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A Novel Combination of Answer Set Programming with Description Logics for the Semantic Web

by Thomas Lukasiewicz - IN PROC. KR-2004 , 2004
"... Abstract. We present a novel combination of disjunctive logic programs under the answer set semantics with description logics for the Semantic Web. The combination is based on a well-balanced interface between disjunctive logic programs and description logics, which guarantees the decidability of th ..."
Abstract - Cited by 288 (60 self) - Add to MetaCart
Abstract. We present a novel combination of disjunctive logic programs under the answer set semantics with description logics for the Semantic Web. The combination is based on a well-balanced interface between disjunctive logic programs and description logics, which guarantees the decidability of the resulting formalism without assuming syntactic restrictions. We show that the new formalism has very nice semantic properties. In particular, it faithfully extends both disjunctive programs and description logics. Furthermore, we describe algorithms for reasoning in the new formalism, and we give a precise picture of its computational complexity. We also provide a special case with polynomial data complexity. 1
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clasp: A conflict-driven answer set solver

by Martin Gebser, Benjamin Kaufmann, André Neumann, Torsten Schaub - In LPNMR’07 , 2007
"... Abstract. We describe the conflict-driven answer set solver clasp, whichis based on concepts from constraint processing (CSP) and satisfiability checking (SAT). We detail its system architecture and major features, and provide a systematic empirical evaluation of its features. 1 ..."
Abstract - Cited by 108 (9 self) - Add to MetaCart
Abstract. We describe the conflict-driven answer set solver clasp, whichis based on concepts from constraint processing (CSP) and satisfiability checking (SAT). We detail its system architecture and major features, and provide a systematic empirical evaluation of its features. 1
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Potassco: The Potsdam Answer Set Solving Collection

by Martin Gebser, Benjamin Kaufmann, Max Ostrowski, Torsten Schaub, Marius Schneider , 2011
"... This paper gives an overview of the open source project Potassco, the Potsdam Answer Set Solving Collection, bundling tools for Answer Set Programming developed at the University of Potsdam. ..."
Abstract - Cited by 98 (15 self) - Add to MetaCart
This paper gives an overview of the open source project Potassco, the Potsdam Answer Set Solving Collection, bundling tools for Answer Set Programming developed at the University of Potsdam.

A uniform integration of higher-order reasoning and external evaluations in answer-set programming

by Thomas Eiter, Giovambattista Ianni, Roman Schindlauer, Hans Tompits - In Proceedings of the 19th International Joint Conference on Artificial Intelligence (IJCAI-05 , 2005
"... We introduce HEX programs, which are nonmonotonic logic programs admitting higher-order atoms as well as external atoms, and we extend the wellknown answer-set semantics to this class of programs. Higher-order features are widely acknowledged as useful for performing meta-reasoning, among other task ..."
Abstract - Cited by 98 (41 self) - Add to MetaCart
We introduce HEX programs, which are nonmonotonic logic programs admitting higher-order atoms as well as external atoms, and we extend the wellknown answer-set semantics to this class of programs. Higher-order features are widely acknowledged as useful for performing meta-reasoning, among other tasks. Furthermore, the possibility to exchange knowledge with external sources in a fully declarative framework such as Answer-Set Programming (ASP) is nowadays important, in particular in view of applications in the Semantic Web area. Through external atoms, HEX programs can model some important extensions to ASP, and are a useful KR tool for expressing various applications. Finally, complexity and implementation issues for a preliminary prototype are discussed. 1

Logic Programming with Ordered Disjunction

by Gerhard Brewka - In Proceedings of AAAI-02 , 2002
"... Logic programs with ordered disjunction (LPODs) combine ideas underlying Qualitative Choice Logic (Brewka, Benferhat, & Le Berre 2002) and answer set programming. Logic programming under answer set semantics is extended with a new connective called ordered disjunction. The new connective allows ..."
Abstract - Cited by 96 (8 self) - Add to MetaCart
Logic programs with ordered disjunction (LPODs) combine ideas underlying Qualitative Choice Logic (Brewka, Benferhat, & Le Berre 2002) and answer set programming. Logic programming under answer set semantics is extended with a new connective called ordered disjunction. The new connective allows us to represent alternative, ranked options for problem solutions in the heads of rules: A × B intuitively means: if possible A, but if A is not possible then at least B. The semantics of logic programs...

Semi-Stable Semantics

by Martin Caminada , 2003
"... In this paper, we examine an argument-based semantics called semistable semantics. Semi-stable semantics is quite close to traditional stable semantics in the sense that every stable extension is also a semi-stable extension. One of the advantages of semi-stable semantics is that there exists at le ..."
Abstract - Cited by 93 (13 self) - Add to MetaCart
In this paper, we examine an argument-based semantics called semistable semantics. Semi-stable semantics is quite close to traditional stable semantics in the sense that every stable extension is also a semi-stable extension. One of the advantages of semi-stable semantics is that there exists at least one semi-stable extension. Furthermore, if there also exists at least one stable extension, then the semi-stable extensions coincide with the stable extensions. This, and other properties, make semi-stable semantics an attractive alternative for the more traditional stable semantics, which until now has been widely used in fields such as logic programming and answer set programming.

Probabilistic reasoning with answer sets

by Chitta Baral, Michael Gelfond, Nelson Rushton - In Proceedings of LPNMR-7 , 2004
"... Abstract. We give a logic programming based account of probability and describe a declarative language P-log capable of reasoning which combines both logical and probabilistic arguments. Several non-trivial examples illustrate the use of P-log for knowledge representation. 1 ..."
Abstract - Cited by 91 (11 self) - Add to MetaCart
Abstract. We give a logic programming based account of probability and describe a declarative language P-log capable of reasoning which combines both logical and probabilistic arguments. Several non-trivial examples illustrate the use of P-log for knowledge representation. 1

Consistent Query Answering: Five Easy Pieces

by Jan Chomicki , 2007
"... Consistent query answering (CQA) is an approach to querying inconsistent databases without repairing them first. This invited talk introduces the basics of CQA, and discusses selected issues in this area. The talk concludes with a summary of other relevant work and an outline of potential future r ..."
Abstract - Cited by 82 (3 self) - Add to MetaCart
Consistent query answering (CQA) is an approach to querying inconsistent databases without repairing them first. This invited talk introduces the basics of CQA, and discusses selected issues in this area. The talk concludes with a summary of other relevant work and an outline of potential future research topics.

Reconciling description logics and rules

by Boris Motik, Riccardo Rosati , 2010
"... Description logics (DLs) and rules are formalisms that emphasize different aspects of knowledge representation: whereas DLs are focused on specifying and reasoning about conceptual knowledge, rules are focused on nonmonotonic inference. Many applications, however, require features of both DLs and ru ..."
Abstract - Cited by 81 (0 self) - Add to MetaCart
Description logics (DLs) and rules are formalisms that emphasize different aspects of knowledge representation: whereas DLs are focused on specifying and reasoning about conceptual knowledge, rules are focused on nonmonotonic inference. Many applications, however, require features of both DLs and rules. Developing a formalism that integrates DLs and rules would be a natural outcome of a large body of research in knowledge representation and reasoning of the last two decades; however, achieving this goal is very challenging and the approaches proposed thus far have not fully reached it. In this paper, we present a hybrid formalism of MKNF + knowledge bases, which integrates DLs and rules in a coherent semantic framework. Achieving seamless integration is nontrivial, since DLs use an open-world assumption, while the rules are based on a closed-world assumption. We overcome this discrepancy by basing the semantics of our formalism on the logic of minimal knowledge and negation as failure (MKNF) by Lifschitz. We present several algorithms for reasoning with MKNF + knowledge bases, each suitable to different kinds of rules, and establish tight complexity bounds.

S.: Gringo: A new grounder for answer set programming

by Martin Gebser, Torsten Schaub, Sven Thiele - In Baral et al , 2007
"... Abstract. We describe a new grounder system for logic programs under answer set semantics, called GrinGo. Our approach combines and extends techniques from the two primary grounding approaches of lparse and dlv. A major emphasis lies on an extensible design that allows for an easy incorporation of n ..."
Abstract - Cited by 78 (14 self) - Add to MetaCart
Abstract. We describe a new grounder system for logic programs under answer set semantics, called GrinGo. Our approach combines and extends techniques from the two primary grounding approaches of lparse and dlv. A major emphasis lies on an extensible design that allows for an easy incorporation of new language features in an efficient system environment. 1 Motivation, Features, and System Architecture A major advantage of Answer Set Programming (ASP; [1]) is its rich modeling language. Paired with high-performance solver technology, it has made ASP a popular tool for declarative problem solving. As a consequence, all ASP solvers rely on sophisticated preprocessing techniques for dealing with the rich input language. The primary purpose of preprocessing is to accomplish an effective variable substitution in the input program. This is why these preprocessors are often referred to as grounders. Although there is meanwhile quite a variety of ASP solvers, there are merely two major grounders, namely lparse [2] and dlv’s grounding component [3]. We enrich this underrepresented area and present a new grounder, called GrinGo, that combines and
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