In this paper, we propose an extension of the well-founded and stable model semantics for logic programs with aggregates. Our approach uses Approximation theory, a fixpoint theory of stable and well-founded fixpoints ...
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Fuzzy answer set programming (FASP) is a recent formalism for knowledge representation that enriches the declarativity of answer set programming by allowing propositions to be graded. To now, no implementations of FAS...
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Fuzzy answer set programming (FASP) is a recent formalism for knowledge representation that enriches the declarativity of answer set programming by allowing propositions to be graded. To now, no implementations of FASP solvers are available and all current proposals are based on compilations of logic programs into different paradigms, like mixed integer programs or bilevel programs. these approaches introduce many auxiliary variables which might affect the performance of a solver negatively. To limit this downside, operators for approximating fuzzy answer sets can be introduced: Given a FASP program, these operators compute lower and upper bounds for all atoms in the program such that all answer sets are between these bounds. this paper analyzes several operators of this kind which are based on linear programming, fuzzy unfounded sets and source pointers. Furthermore, the paper reports on a prototypical implementation, also describing strategies for avoiding computations of these operators when they are guaranteed to not improve current bounds. the operators and their implementation can be used to obtain more constrained mixed integer or bilevel programs, or even for providing a basis for implementing a native FASP solver. Interestingly, the semantics of relevant classes of programs with unique answer sets, like positive programs and programs with stratified negation, can be already computed by the prototype without the need for an external tool.
Concurrent functional languages that are endowed with symbolic reasoning capabilities such as Maude offer a high-level, elegant, and efficient approach to programming and analyzing complex, highly nondeterministic sof...
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Concurrent functional languages that are endowed with symbolic reasoning capabilities such as Maude offer a high-level, elegant, and efficient approach to programming and analyzing complex, highly nondeterministic software systems. Maude's symbolic capabilities are based on equational unification and narrowing in rewrite theories, and provide Maude with advanced logicprogramming capabilities such as unification modulo user-definable equational theories and symbolic reachability analysis in rewrite theories. Intricate computing problems may be effectively and naturally solved in Maude thanks to the synergy of these recently developed symbolic capabilities and classical Maude features, such as: (i) rich type structures with sorts (types), subsorts, and overloading;(ii) equational rewriting modulo various combinations of axioms such as associativity, commutativity, and identity;and (iii) classical reachability analysis in rewrite theories. However, the combination of all of these features may hinder the understanding of Maude symbolic computations for non-experienced developers. the purpose of this article is to describe how programming and analysis of Maude rewrite theories can be made easier by providing a sophisticated graphical tool called Narval that supports the fine-grained inspection of Maude symbolic computations.
Albeit temporal reasoning and modularity are very prolific fields of research in logicprogramming (LP) we find few examples of their integration. Moreover, in those examples, time and modularity are considered orthog...
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ISBN:
(纸本)9783642006746
Albeit temporal reasoning and modularity are very prolific fields of research in logicprogramming (LP) we find few examples of their integration. Moreover, in those examples, time and modularity are considered orthogonal to each other. In this paper we propose the addition of temporal annotations to a modular extension of LP such that the usage of a, module is influenced by temporal conditions. Besides illustrative examples we also provide all operational semantics together with a compiler, allowing this way for the development of applications based on such language.
this paper adds the handling of negative information to a functional-logic deductive database language. By adopting as semantics for negation the so-called CRWLF, wherein the negation is intended as’finite failure’ ...
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Set constraints are inclusion relations between expressions denoting sets of ground terms over a ranked alphabet. they are the main ingredient in set-based program analysis. In this paper we describe a constraint logi...
Set constraints are inclusion relations between expressions denoting sets of ground terms over a ranked alphabet. they are the main ingredient in set-based program analysis. In this paper we describe a constraint logicprogramming language CLP(SC) over set constraints in the style of J. Jaffar and J.-L. Lassez (1987, "Proc. Symp. Principles of programming Languages 1987," pp. 111-119). the language subsumes ordinary logic programs over an Herbrand domain. We give an efficient unification algorithm and operational, declarative, and fixpoint semantics. We sh ow how the language can be applied in set-based program analysis by deriving explicitly the monadic approximation of the collecting semantics of N. Heintze and J. Jaffar (1992, "Set Based Program Analysis";1990, "Proc. 17th Symp. Principles of programming Languages," pp, 197-209). (C) 1998 Academic Press.
In this paper we investigate how to integrate the XQuery language and logicprogramming. Withthis aim, we represent XML documents by means of a logic program. this logic program represents the document schema by mean...
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ISBN:
(纸本)9783642006746
In this paper we investigate how to integrate the XQuery language and logicprogramming. Withthis aim, we represent XML documents by means of a logic program. this logic program represents the document schema by means of rules and the document itself by means of facts. Now, XQuery expressions can be integrated into logicprogramming by considering a translation (i.e. encoding) of for-let-where-return expressions by means of logic rules and a goal.
Continuing a line of work by Abramsky (1994), by Bellin and Scott (1994), and by Caires and Pfenning (2010), among others, this paper presents CP, a calculus in which propositions of classical linear logic correspond ...
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ISBN:
(纸本)9781450310543
Continuing a line of work by Abramsky (1994), by Bellin and Scott (1994), and by Caires and Pfenning (2010), among others, this paper presents CP, a calculus in which propositions of classical linear logic correspond to session types. Continuing a line of work by Honda (1993), by Honda, Kubo, and Vasconcelos (1998), and by Gay and Vasconcelos (2010), among others, this paper presents GV, a linear functional language with session types, and presents a translation from GV into CP. the translation formalises for the first time a connection between a standard presentation of session types and linear logic, and shows how a modification to the standard presentation yield a language free from deadlock, where deadlock freedom follows from the correspondence to linear logic.
Recent development of logicprogramming languages based on linear logic suggests a successful direction to extend logicprogramming to be more expressive and more efficient. the treatment of formulasas- resources give...
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