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27
Logic Programming and Knowledge Representation
 Journal of Logic Programming
, 1994
"... In this paper, we review recent work aimed at the application of declarative logic programming to knowledge representation in artificial intelligence. We consider exten sions of the language of definite logic programs by classical (strong) negation, disjunc tion, and some modal operators and sh ..."
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Cited by 227 (21 self)
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In this paper, we review recent work aimed at the application of declarative logic programming to knowledge representation in artificial intelligence. We consider exten sions of the language of definite logic programs by classical (strong) negation, disjunc tion, and some modal operators and show how each of the added features extends the representational power of the language.
Nested expressions in logic programs
 Annals of Mathematics and Artificial Intelligence
, 1999
"... We extend the answer set semantics to a class of logic programs with nested expressions permitted in the bodies and heads of rules. These expressions are formed from literals using negation as failure, conjunction (,) and disjunction (;) that can be nested arbitrarily. Conditional expressions are in ..."
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Cited by 112 (13 self)
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We extend the answer set semantics to a class of logic programs with nested expressions permitted in the bodies and heads of rules. These expressions are formed from literals using negation as failure, conjunction (,) and disjunction (;) that can be nested arbitrarily. Conditional expressions are introduced as abbreviations. The study of equivalent transformations of programs with nested expressions shows that any such program is equivalent to a set of disjunctive rules, possibly with negation as failure in the heads. The generalized answer set semantics is related to the LloydTopor generalization of Clark's completion and to the logic of minimal belief and negation as failure.
Minimal Belief and Negation as Failure
 Artificial Intelligence
, 1994
"... Fangzhen Lin and Yoav Shoham defined a propositional nonmonotonic logic which uses two independent modal operators. One of them represents minimal knowledge, the other is related to the ideas of justification (as understood in default logic) and of negation as failure. We describe a simplified versi ..."
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Cited by 72 (5 self)
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Fangzhen Lin and Yoav Shoham defined a propositional nonmonotonic logic which uses two independent modal operators. One of them represents minimal knowledge, the other is related to the ideas of justification (as understood in default logic) and of negation as failure. We describe a simplified version of that system, show how quantifiers can be included in it, and study its relation to circumscription and default logic, to logic programming, and to the theory of epistemic queries developed by Hector Levesque and Ray Reiter. 1 Introduction Lin and Shoham [16] defined a propositional nonmonotonic logic which uses two independent modal operators. One of them represents minimal knowledge, 1 the other is related to the ideas of justification (as understood in default logic) and of negation as failure. In this paper, we consider a special case of that system, in which Kripke structures of a particularly simple kind are used, and show how quantifiers can be included in it. This extension i...
Stable models and circumscription
 Artificial Intelligence
"... The concept of a stable model provided a declarative semantics for Prolog programs with negation as failure and became a starting point for the development of answer set programming. In this paper we propose a new definition of that concept, which covers many constructs used in answer set programmin ..."
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Cited by 52 (36 self)
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The concept of a stable model provided a declarative semantics for Prolog programs with negation as failure and became a starting point for the development of answer set programming. In this paper we propose a new definition of that concept, which covers many constructs used in answer set programming and, unlike the original definition, refers neither to grounding nor to fixpoints. It is based on a syntactic transformation similar to parallel circumscription. 1
Extended Logic Programs as Autoepistemic Theories
 In Proceedings of the Second Int'l Workshop on Logic Programming and Nonmonotonic Reasoning
, 1993
"... Recent research on applications of nonmonotonic reasoning to the semantics of logic programs demonstrates that some nonmonotonic formalisms are better suited for such use than others. Circumscription is applicable as long as the programs under consideration are stratified. To describe the semantics ..."
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Cited by 35 (1 self)
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Recent research on applications of nonmonotonic reasoning to the semantics of logic programs demonstrates that some nonmonotonic formalisms are better suited for such use than others. Circumscription is applicable as long as the programs under consideration are stratified. To describe the semantics of general logic programs without the stratification assumption, one has to use autoepistemic logic or default logic. When Gelfond and Lifschitz extended this work to programs with classical negation, they used default logic, because it was not clear whether autoepistemic logic could be applied in that wider domain. In this paper we show that programs with classical negation can be, in fact, easily represented by autoepistemic theories. We also prove that an even simpler embedding is possible if reflexive autoepistemic logic is used. Both translations are applicable to disjunctive programs as well. 1 Introduction Recent research on applications of nonmonotonic reasoning to the semantics of ...
Nondeterministic Action and Dominance: Foundations for Planning and Qualitative Decision
 In Proceedings of the TARK'96
, 1996
"... ..."
Inconsistency tolerance in p2p data integration: an epistemic logic approach
 IN PROC. OF THE 10TH INT. WORKSHOP ON DATABASE PROGRAMMING LANGUAGES (DBPL
, 2005
"... We study peertopeer data integration, where each peer models an autonomous system that exports data in terms of its own schema, and data interoperation is achieved by means of mappings among the peer schemas, rather than through a global schema. We propose a multimodal epistemic semantics based ..."
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Cited by 24 (4 self)
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We study peertopeer data integration, where each peer models an autonomous system that exports data in terms of its own schema, and data interoperation is achieved by means of mappings among the peer schemas, rather than through a global schema. We propose a multimodal epistemic semantics based on the idea that each peer is conceived as a rational agent that exchanges knowledge/belief with other peers, thus nicely modeling the modular structure of the system. We then address the issue of dealing with possible inconsistencies, and distinguish between two types of inconsistencies, called local and P2P, respectively. We define a nonmonotonic extension of our logic that is able to reason on the beliefs of peers under inconsistency tolerance. Tolerance to local inconsistency essentially means that the presence of inconsistency within one peer does not affect the consistency of the whole system. Tolerance to P2P inconsistency means being able to resolve inconsistencies arising from the interaction between peers. We study query answering and its data complexity in this setting, and we present an algorithm that is sound and complete with respect to the proposed semantics, and optimal with respect to worstcase complexity.
Reformulating the Situation Calculus and the Event Calculus in the General Theory of Stable Models and in Answer Set Programming
"... Circumscription and logic programs under the stable model semantics are two wellknown nonmonotonic formalisms. The former has served as a basis of classical logic based action formalisms, such as the situation calculus, the event calculus and temporal action logics; the latter has served as a basis ..."
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Cited by 7 (5 self)
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Circumscription and logic programs under the stable model semantics are two wellknown nonmonotonic formalisms. The former has served as a basis of classical logic based action formalisms, such as the situation calculus, the event calculus and temporal action logics; the latter has served as a basis of a family of action languages, such as language A and several of its descendants. Based on the discovery that circumscription and the stable model semantics coincide on a class of canonical formulas, we reformulate the situation calculus and the event calculus in the general theory of stable models. We also present a translation that turns the reformulations further into answer set programs, so that efficient answer set solvers can be applied to compute the situation calculus and the event calculus. 1.
Autoepistemic Logic As A Unified Basis For Nonmonotonic Reasoning
, 1993
"... Autoepistemic logic is investigated in a general setting where autoepistemic reasoning based on a given classical logic is studied. The possible sets of autoepistemic conclusions from a set of premises are defined in terms of expansions of the premises. First Moore style expansions defined by a fixe ..."
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Cited by 5 (1 self)
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Autoepistemic logic is investigated in a general setting where autoepistemic reasoning based on a given classical logic is studied. The possible sets of autoepistemic conclusions from a set of premises are defined in terms of expansions of the premises. First Moore style expansions defined by a fixed point equation are considered and a simple finitary characterization of expansions is developed. An alternative definition is proposed where autoepistemic reasoning is formalized as a sequence of introspection steps using an enumeration of sentences. The resulting enumerationbased expansions are a proper subclass of Moore style expansions. An even more tightly grounded subclass is captured by considering only Lhierarchic enumerations. Finitary characterizations of enumerationbased and Lhierarchic expansions are developed. It is shown that autoepistemic reasoning based on Moore style, enumerationbased, and Lhierarchic expansions is decidable if the monotonic consequence relation giv...
Well Founded Semantics as Twodimensional HereandThere
 in Proceedings of ASP 01, 2001 AAAI Spring Symposium Series
, 2001
"... This work presents a new logical characterization of well founded semantics that provides, as interesting innovation, a fully semanticoriented treatment of program connectives without relying on any syntactic restriction or transformation. Our work is inspired by a recent research line which h ..."
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Cited by 4 (2 self)
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This work presents a new logical characterization of well founded semantics that provides, as interesting innovation, a fully semanticoriented treatment of program connectives without relying on any syntactic restriction or transformation. Our work is inspired by a recent research line which has established a nice correspondence between stable models and a particular minimization for the monotonic logic of hereandthere. We identify a generalization of the latter (we have called twodimensional hereandthere) that captures Przymusinki 's 3valued stable models and show that, as in the 2valued case, the hereandthere version is more economical in the set of models involved in the minimization process.