In this paper we introduce a logicprogramming based framework which allows the representation of conditional non-monotonic temporal beliefs and goals in a declarative way. We endow it with stable model like semantics...
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ISBN:
(纸本)9783642405648
In this paper we introduce a logicprogramming based framework which allows the representation of conditional non-monotonic temporal beliefs and goals in a declarative way. We endow it with stable model like semantics that allows us to deal with conflicting goals and generate possible alternatives. We show that our framework satisfies some usual properties on goals and that it allows imposing alternative constraints on the interaction between beliefs and goals. We prove the decidability of the usual reasoning tasks and show how they can be implemented using an ASP solver and an LTL reasoner in a modular way, thus taking advantage of existing LTL reasoners and ASP solvers.
Norms and regulations play an important role in the governance of human society. Social rules Such as laws, conventions and contracts prescribe and regulate our behaviour, however it is possible for us to break these ...
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ISBN:
(纸本)9783642042379
Norms and regulations play an important role in the governance of human society. Social rules Such as laws, conventions and contracts prescribe and regulate our behaviour, however it is possible for us to break these rules at our discretion and face the consequences. By providing the means to describe and reason about norms in a computational context, normative frameworks may be applied to software systems allowing for automated reasoning about the consequences of socially acceptable and unacceptable behaviour. In this paper, we outline our mathematical formulation for normative frameworks and describe how its semantics can be represented in ASP. thus enabling the construction of models of normative systems that can be subjected to formal verification and that can act as functional repositories of normative knowledge for the software components that participate in them.
A concentrator is a circuit with N inputs and M <= N outputs that can route any given subset of K <= M valid inputs to K of its M outputs. Concentrator circuits are important building blocks of many parallel alg...
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ISBN:
(纸本)9783319616605;9783319616599
A concentrator is a circuit with N inputs and M <= N outputs that can route any given subset of K <= M valid inputs to K of its M outputs. Concentrator circuits are important building blocks of many parallel algorithms. the design of optimal concentrator circuits is however a challenging task that has already been considered in many research papers. In this paper, we show how answer set programming can be used to automatically generate concentrator circuits of provably optimal size.
dlv is a knowledge representation system, based on disjunctive logicprogramming, which offers front-ends to several advanced KR formalisms. this paper describes new techniques for the computation of answer sets of di...
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ISBN:
(纸本)3540667490
dlv is a knowledge representation system, based on disjunctive logicprogramming, which offers front-ends to several advanced KR formalisms. this paper describes new techniques for the computation of answer sets of disjunctive logic programs, that have been developed and implemented in the dlv system. these techniques try to "push" the query goals in the process of model generation (query goals are often present either explicitly, like in planning and diagnosis, or implicitly in the form of integrity constraints). this way, a lot of useless models are discarded "a priori" and the computation converges rapidly toward the generation of the "right" answer set. A few preliminary benchmarks show dramatic efficiency gains due to the new techniques.
Equilibrium logic, introduced by David Pearce, extends the concept of an answer set from logic programs to arbitrary sets of formulas. logic programs correspond to the special case in which every formula is a "ru...
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ISBN:
(纸本)3540285385
Equilibrium logic, introduced by David Pearce, extends the concept of an answer set from logic programs to arbitrary sets of formulas. logic programs correspond to the special case in which every formula is a "rule" - an implication that has no implications in the antecedent (body) and consequent (head). the semantics of equilibrium logic looks very different from the usual definitions of an answer set in logicprogramming, as it is based on Kripke models. In this paper we propose a new definition of equilibrium logic which uses the concept of a reduct, as in the standard definition of an answer set. Second, we apply the generalized concept of an answer set to the problem of defining the semantics of aggregates in answer set programming. We propose, in particular, a semantics for weight constraints that covers the problematic case of negative weights. Our semantics of aggregates is an extension of the approach due to Faber, Leone, and Pfeifer to a language with choice rules and, more generally, arbitrary rules with nested expressions.
Several proposals of the semantics of aggregates are based oil different extensions of the stable model semantics, which makes it difficult to compare them. In this note, building upon a reductive approach to designin...
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ISBN:
(纸本)9783642042379
Several proposals of the semantics of aggregates are based oil different extensions of the stable model semantics, which makes it difficult to compare them. In this note, building upon a reductive approach to designing aggregates, we provide reformulations of some existing semantics in terms of propositional formulas, which help us compare the semanitcs and understand their properties in terms of their propositional formula representations. We also present a generalization of semantics of aggregates without involving grounding, and define loop formulas for programs with aggregates guided by the reductive approach.
Answer Set programming (ASP) is a well-established declarative programming language based on logic. the success of ASP is mainly due to the availability of efficient ASP solvers, therefore their development is still a...
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ISBN:
(纸本)9783030205287;9783030205270
Answer Set programming (ASP) is a well-established declarative programming language based on logic. the success of ASP is mainly due to the availability of efficient ASP solvers, therefore their development is still an important research topic. In this paper we report the recent improvements of the well-known ASP solver WASP. the new version of WASP includes several improvements of the main solving strategies and advanced reasoning techniques for computing paracoherent answer sets. Indeed, WASP is the first ASP solver handling paracoherent reasoning under two mainstream semantics, namely semi-stable and semiequilibrium. However, semi-equilibrium semantics may require the introduction of several disjunctive rules, which are usually considered as a source of inefficiency for modern solvers. Such a drawback is addressed in WASP by implementing ad-hoc techniques to efficiently handle disjunctive logic programs. these techniques are presented and evaluated in this paper.
We present many-valued disjunctive logic programs in which classical disjunctive logic program clauses are extended by a truth value that respects the material implication. Interestingly, these many-valued disjunctive...
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ISBN:
(纸本)3540667490
We present many-valued disjunctive logic programs in which classical disjunctive logic program clauses are extended by a truth value that respects the material implication. Interestingly, these many-valued disjunctive logic programs have both a probabilistic semantics in probabilities over possible worlds and a truth-functional semantics. We then define minimal, perfect, and stable models and show that they have the same properties like their classical counterparts. In particular, perfect and stable models are always minimal models. Under local stratification, the perfect model semantics coincides withthe stable model semantics. Finally, we show that some special cases of propositional many-valued disjunctive logicprogramming under minimal, perfect, and stable model semantics have the same complexity like their classical counterparts.
the addition of preferences to normal logic pro-rams is a convenient way to represent many aspects of default reasoning. If the derivation of an atom A(1) is preferred to that of an atom A(2) a preference rule can be ...
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the addition of preferences to normal logic pro-rams is a convenient way to represent many aspects of default reasoning. If the derivation of an atom A(1) is preferred to that of an atom A(2) a preference rule can be defined so that A(2) is derived only if A(1) is not. Although such situations can be modelled directly using default negation, it is often easier to define preference rules than it is to add negation to the bodies of rules. As first noted by Govindarajan et al. [Proc. Internat. Conf. on logicprogramming, 1995, pp. 731-746], for certain grammars, it may be easier to disambiguate parses using preferences than by enforcing disambiguation in the grammar rules themselves. In this paper we define a general fixed-point semantics for preference logic programs based on an embedding into the well-founded semantics, and discuss its features and relation to previous preference logic semantics. We then study how preference logic grammars are used in data standardization, the commercially important process of extracting useful information from poorly structured textual data. this process includes correcting misspellings and truncations that occur in data, extraction of relevant C, 41 information via parsing, and correcting inconsistencies in the extracted information. the declarativity of Prolog offers natural advantages for data standardization, and a commercial standardizer has been implemented using Prolog. However, we show that the use of preference logic grammars allow construction of a much more powerful and declarative commercial standardizer, and discuss in detail how the use of the non-monotonic construct of preferences leads to improved commercial software. (C) 2002 Elsevier Science B.V. All rights reserved.
this book constitutes the refereed proceedings of the 4thinternationalconference on logicprogramming and nonmonotonicreasoning, LPNMR '97, held in Dagstuhl Castle, Germany, in July 1997.;the volume presents 19...
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ISBN:
(数字)9783540692492
ISBN:
(纸本)9783540632559
this book constitutes the refereed proceedings of the 4thinternationalconference on logicprogramming and nonmonotonicreasoning, LPNMR '97, held in Dagstuhl Castle, Germany, in July 1997.;the volume presents 19 revised regular papers together with 10 system descriptions and five abstracts of invited presentations. the papers included report state-of-the-art research and development in the interdisciplinary area of logicprogramming and logical foundations of artificial intelligence.
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