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Extending Classical Logic with Inductive Definitions
, 2000
"... The goal of this paper is to extend classical logic with a generalized notion of inductive definition supporting positive and negative induction, to investigate the properties of this logic, its relationships to other logics in the area of nonmonotonic reasoning, logic programming and deductiv ..."
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Cited by 58 (38 self)
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The goal of this paper is to extend classical logic with a generalized notion of inductive definition supporting positive and negative induction, to investigate the properties of this logic, its relationships to other logics in the area of nonmonotonic reasoning, logic programming and deductive databases, and to show its application for knowledge representation by giving a typology of definitional knowledge.
Abductive logic programming with CIFF: Implementation and applications
 University of Parma
, 2004
"... Abstract. We describe a system implementing a novel extension of Fung and Kowalski’s IFF abductive proof procedure which we call CIFF, and its application to realise intelligent agents that can construct (partial or complete) plans and react to changes in the environment. CIFF extends the original I ..."
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Cited by 12 (5 self)
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Abstract. We describe a system implementing a novel extension of Fung and Kowalski’s IFF abductive proof procedure which we call CIFF, and its application to realise intelligent agents that can construct (partial or complete) plans and react to changes in the environment. CIFF extends the original IFF procedure in two ways: by dealing with constraint predicates and by dealing with nonallowed abductive logic programs. 1
Logic Programming Approaches for Representing and Solving Constraint Satisfaction Problems: A Comparison
 Proceedings of the 7th International Conference on Logic for Programming and Automated Reasoning, volume 1955 of Lecture Notes in Arti Intelligence
, 2000
"... . Many logic programming based approaches can be used to describe and solve combinatorial search problems. On the one hand there is constraint logic programming which computes a solution as an answer substitution to a query containing the variables of the constraint satisfaction problem. On the ..."
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Cited by 9 (2 self)
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. Many logic programming based approaches can be used to describe and solve combinatorial search problems. On the one hand there is constraint logic programming which computes a solution as an answer substitution to a query containing the variables of the constraint satisfaction problem. On the other hand there are systems based on stable model semantics, abductive systems, and rst order logic model generators which compute solutions as models of some theory. This paper compares these dierent approaches from the point of view of knowledge representation (how declarative are the programs) and from the point of view of performance (how good are they at solving typical problems). 1 Introduction Consistency techniques are widely used for solving nite domain constraint satisfaction problems (CSP) [19]. These techniques have been integrated in logic programming, resulting in nite domain constraint logic programming (CLP) [20]. In this paradigm, a program typically creates a da...
A Comparison of Logic Programming Approaches for Representation and Solving of Constraint Satisfaction Problems
 8th International Workshop on NonMonotonic Reasoning, Special Session on Abduction
, 2000
"... Many logic programming based approaches can be used to describe and solve combinatorial search problems. On the one hand there are definite programs and constraint logic programs that compute a solution as an answer substitution to a query containing the variables of the constraint satisfaction prob ..."
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Cited by 7 (3 self)
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Many logic programming based approaches can be used to describe and solve combinatorial search problems. On the one hand there are definite programs and constraint logic programs that compute a solution as an answer substitution to a query containing the variables of the constraint satisfaction problem. On the other hand there are approaches based on stable model semantics, abduction, and firstorder logic model generation that compute solutions as models of some theory. This paper compares these different approaches from point of view of knowledge representation (how declarative are the programs) and from point of view of performance (how good are they at solving typical problems).
Problem solving in IDlogic with aggregates: some experiments
 8TH INT. WORKSHOP ON NONMONOTONIC REASONING (NMR2000), SESSION ON ABDUCTION
, 2000
"... The goal of the LP+ project at the K.U.Leuven is to design an expressive logic, suitable for declarative knowledge representation, and to develop intelligent systems based on Logic Programming technology for solving computational problems using the declarative specications. The IDlogic is an integr ..."
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Cited by 2 (2 self)
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The goal of the LP+ project at the K.U.Leuven is to design an expressive logic, suitable for declarative knowledge representation, and to develop intelligent systems based on Logic Programming technology for solving computational problems using the declarative specications. The IDlogic is an integration of typed classical logic and a definition logic. Different abductive solvers for this language are being developed. This paper is a report of the integration of high order aggregates into IDlogic and the consequences on the solver SLDNFA.
Abductive Reasoning with Temporal Information
 Proceedings of the Fourth International Workshop on Computational Semantics
, 2001
"... Texts in natural language contain a lot of temporal information, both explicit and implicit. Verbs and temporal adjuncts carry most of the explicit information, but for a full understanding general world knowledge and default assumptions have to be taken into account. We will present a theory fo ..."
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Cited by 1 (1 self)
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Texts in natural language contain a lot of temporal information, both explicit and implicit. Verbs and temporal adjuncts carry most of the explicit information, but for a full understanding general world knowledge and default assumptions have to be taken into account. We will present a theory for describing the relation between, on the one hand, verbs, their tenses and adjuncts and, on the other, the eventualities and periods of time they represent and their relative temporal locations, while allowing interaction with general world knowledge.
Logic Programming for Describing and Solving Planning Problems
, 2000
"... A logic programming paradigm which expresses solutions to problems as stable models has recently been promoted as a declarative approach to solving various combinatorial and search problems, including planning problems. In this paradigm, all program rules are considered as constraints and solut ..."
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Cited by 1 (0 self)
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A logic programming paradigm which expresses solutions to problems as stable models has recently been promoted as a declarative approach to solving various combinatorial and search problems, including planning problems. In this paradigm, all program rules are considered as constraints and solutions are stable models of the rule set. This is a rather radical departure from the standard paradigm of logic programming. In this paper we revisit abductive logic programming and argue that it allows a programming style which is as declarative as programming based on stable models. However, within abductive logic programming, one has two kinds of rules. On the one hand predicate definitions (which may depend on the abducibles) which are nothing else than standard logic programs (with their nonmonotonic semantics when containing with negation); on the other hand rules which constrain the models for the abducibles. In this sense abductive logic programming is a smooth extension of the standard paradigm of logic programming, not a radical departure. keywords: planning, abduction, nonmonotonic reasoning.
Semantic Interpretation of Temporal Information By Abductive Inference
"... Besides temporal information explicitly available in verbs and adjuncts, the temporal interpretation of a text also depends on general world knowledge and default assumptions. We will present a theory for describing the relation between, on the one hand, verbs, their tenses and adjuncts and, on the ..."
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Besides temporal information explicitly available in verbs and adjuncts, the temporal interpretation of a text also depends on general world knowledge and default assumptions. We will present a theory for describing the relation between, on the one hand, verbs, their tenses and adjuncts and, on the other, the eventualities and periods of time they represent and their relative temporal locations. The theory is formulated in logic and is a practical implementation of the concepts described in Ness Schelkens et al. (this volume). We will show how an abductive resolution procedure can be used on this representation to extract temporal information from texts. 1 Introduction This article presents some work conducted in the framework of Linguaduct, a project on the temporal interpretation of Dutch texts by means of abductive reasoning. A natural language text contains a lot of both explicit and implicit temporal information, mostly in verbs and adjuncts. The purpose of the theory presente...
SLDNFAsystem
"... The SLDNFAsystem results from the LP+ project at the K.U.Leuven, which investigates logics and proof procedures for these logics for declarative knowledge representation. Within this project inductive de nition logic (IDlogic) is used as representation logic. Dierent solvers are being developed fo ..."
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The SLDNFAsystem results from the LP+ project at the K.U.Leuven, which investigates logics and proof procedures for these logics for declarative knowledge representation. Within this project inductive de nition logic (IDlogic) is used as representation logic. Dierent solvers are being developed for this logic and one of these is SLDNFA. A prototype of the system is available and used for investigating how to solve eciently problems represented in IDlogic. General Information The LP+ project at the K.U.Leuven aims at developing and investigating logics suitable for declarative knowledge representation. To be able to represent problem domains in a declarative way, the logic must be capable to express the knowledge of the expert in a natural and graceful way. Therefore a suited logic has to deal with two mayor types of knowledge: de nitional and assertional knowledge (Denecker 1995). This view is incorporated in IDlogic, a conservative extension of classical logic with a ge...
Fages' Theorem For Programs With . . .
 IN: PROC. INTERNATIONAL CONFERENCE ON LOGIC PROGRAMMING
, 2001
"... We extend a theorem by Francois Fages about the relationship between the completion semantics and the answer set semantics of logic programs to a class of programs with nested expressions permitted in the bodies of rules. Fages' theorem is important from the perspective of answer set programming ..."
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We extend a theorem by Francois Fages about the relationship between the completion semantics and the answer set semantics of logic programs to a class of programs with nested expressions permitted in the bodies of rules. Fages' theorem is important from the perspective of answer set programming: whenever the two semantics are equivalent, answer sets can be computed by propositional solvers, such as sato, instead of answer set solvers, such as smodels. The need to extend Fages' theorem to programs with nested expressions is related to the use of choice rules in the input language of smodels.