Página 1 dos resultados de 24808 itens digitais encontrados em 0.021 segundos

## Granlog : um modelo para analise automatica de granulosidade na programacao em logica; Granlog a model for automatic granulariy analysis in logic programming

Barbosa, Jorge Luis Victoria
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
36.69%

## Temporal reasoning in a logic programming language with modularity

Nogueira, Vitor Beires
ENG
Relevância na Pesquisa
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## Default Logic and Autoepistemic Logic: Fixed Points and Common Semantic Framework

Teng, Choh Man
Fonte: University of Rochester. Computer Science Department. Publicador: University of Rochester. Computer Science Department.
Tipo: Relatório
ENG
Relevância na Pesquisa
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When we work with information from multiple sources, the formats of the knowledge bases may not be uniform. It would be desirable to be able to combine a knowledge base of default rules with one containing autoepistemic formulas. Previous works on relating default logic and autoepistemic logic mostly impose some constraints on autoepistemic logic, and thus are not suitable for combining the two logics. We first present a fixed point formulation of autoepistemic logic analogous to that of default logic. Then we introduce a possible world framework with a partition structure, which corresponds to our intuitive notion of accessibility as linking alternate possible' worlds. We show that both default logic and autoepistemic logic can be characterized using this framework, and the constraints imposed on the possible world structures correspond to the requirements in the fixed point formulations. Casting both default logic and autoepistemic logic in a common framework is important for developing a semantics applicable to the two logics, both separately and combined.

## Typed Semigroups, Majority Logic, and Threshold Circuits; Getypte Halbgruppen, Majority Logik und Threshold Schaltkreis

Krebs, Andreas
Tipo: Dissertação
EN
Relevância na Pesquisa
36.67%
In this thesis we focused on the interplay of logic, algebra and circuit theory. While their interaction was previously mainly studied for the case of regular languages we extend the focus to non-regular languages and show that similar connections can be proven. One of the big open questions in circuit theory is whether the classes TC0 and NC1 coincide, which is equivalent to the question whether L_A5 in TC0. In this thesis we established some separation results for subclasses of TC0 that might finally result in a separation of TC0 from NC1. We started by giving an algebraic characterization for arbitrary logic and circuit classes. Of course, any such characterization includes non-regular languages and hence finite semigroups are not sufficient, whereas infinite semigroups are too cumbersome. The key ingredient to this characterization was the typed semigroup which allowed for infinite semigroups, taming them by additional algebraic structures. The theory of typed semigroups coincides with the theory of finite semigroups in the finite case, additionally allowing for finer correspondences, and is a natural extension for the infinite case. The known connections between algebra, logic and circuits were extended in a unifying proof. For this we needed to extend the block product to typed semigroups. One must exercise caution when defining the block product for an infinite structure...

## Sobre os fundamentos de programação lógica paraconsistente; On the foundations of paraconsistent logic programming

Tarcísio Genaro Rodrigues
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Relevância na Pesquisa
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A Programação Lógica nasce da interação entre a Lógica e os fundamentos da Ciência da Computação: teorias de primeira ordem podem ser interpretadas como programas de computador. A Programação Lógica tem sido extensamente utilizada em ramos da Inteligência Artificial tais como Representação do Conhecimento e Raciocínio de Senso Comum. Esta aproximação deu origem a uma extensa pesquisa com a intenção de definir sistemas de Programação Lógica paraconsistentes, isto é, sistemas nos quais seja possível manipular informação contraditória. Porém, todas as abordagens existentes carecem de uma fundamentação lógica claramente definida, como a encontrada na programação lógica clássica. A questão básica é saber quais são as lógicas paraconsistentes subjacentes a estas abordagens. A presente dissertação tem como objetivo estabelecer uma fundamentação lógica e conceitual clara e sólida para o desenvolvimento de sistemas bem fundados de Programação Lógica Paraconsistente. Nesse sentido, este trabalho pode ser considerado como a primeira (e bem sucedida) etapa de um ambicioso programa de pesquisa. Uma das teses principais da presente dissertação é que as Lógicas da Inconsistência Formal (LFI's)...

## Subjetividade, ideias e coisas : estudo crítico e tradução da primeira parte da Lógica de Port-Royal, I-VIII; Subjectivity, ideas and things: a critical study of the first part of the logic of Port-Royal, I-VIII and the translation of the first part

Peixoto, Katarina Ribeiro
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
36.71%

## Boolean Dependence Logic and Partially-Ordered Connectives

Ebbing, Johannes; Hella, Lauri; Lohmann, Peter; Virtema, Jonni
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.66%
We introduce a new variant of dependence logic called Boolean dependence logic. In Boolean dependence logic dependence atoms are of the type =(x_1,...,x_n,\alpha), where \alpha is a Boolean variable. Intuitively, with Boolean dependence atoms one can express quantification of relations, while standard dependence atoms express quantification over functions. We compare the expressive power of Boolean dependence logic to dependence logic and first-order logic enriched by partially-ordered connectives. We show that the expressive power of Boolean dependence logic and dependence logic coincide. We define natural syntactic fragments of Boolean dependence logic and show that they coincide with the corresponding fragments of first-order logic enriched by partially-ordered connectives with respect to expressive power. We then show that the fragments form a strict hierarchy.; Comment: 41 pages

## Mathematical semantics of intuitionistic logic

Melikhov, Sergey A.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.66%
This is an elementary introduction to intuitionistic logic, assuming a modest literacy in mathematics (such as topological spaces and posets) but no training in formal logic. We adopt and develop Kolmogorov's understanding of intuitionistic logic as the logic of schemes of solutions of mathematical problems. Here intuitionistic logic is viewed as an extension package that upgrades classical logic without removing it (in contrast to the standard conception of Brouwer and Heyting, which regards intuitionistic logic as an alternative to classical logic that criminalizes some of its principles). The main purpose of the upgrade comes, for us, from Hilbert's idea of equivalence between proofs of a given theorem, and from the intuition of this equivalence relation as capable of being nontrivial. Mathematically, this idea of "proof-relevance" amounts to categorification. Accordingly, we construct sheaf-valued models of intuitionistic logic, in which conjunction and disjunction are interpreted by product and disjoint union (of sheaves of sets); these can be seen as a categorification of the familiar (since Leibniz, Euler and Venn) models of classical logic, in which conjunction and disjunction are interpreted by intersection and union (of sets). Our sheaf-valued models (not to be confused with the usual open set-valued "sheaf models") turn out to be a special case of Palmgren's categorical models. We prove first-oder intuitionistic logic to be complete with respect to our sheaf-valued semantics.; Comment: 77 pages. Moderate changes...

## The Standard Aspect of Dialectical Logic

Kent, Robert E.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.65%
Dialectical logic is the logic of dialectical processes. The goal of dialectical logic is to introduce dynamic notions into logical computational systems. The fundamental notions of proposition and truth-value in standard logic are subsumed by the notions of process and flow in dialectical logic. Dialectical logic has a standard aspect, which can be defined in terms of the "local cartesian closure" of subtypes. The standard aspect of dialectical logic provides a natural program semantics which incorporates Hoare's precondition/postcondition semantics and extends the standard Kripke semantics of dynamic logic. The goal of the standard aspect of dialectical logic is to unify the logic of small-scale and large-scale programming.; Comment: An abstracted version of this paper, entitled "Dialectical Program Semantics", was accepted for presentation at the 1st International Conference on Algebraic Methodology and Software Technology (AMAST'89), University of Iowa, Iowa City, Iowa, 1989

## The Logic of Partitions: Introduction to the Dual of the Logic of Subsets

Ellerman, David
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.66%
Modern categorical logic as well as the Kripke and topological models of intuitionistic logic suggest that the interpretation of ordinary "propositional" logic should in general be the logic of subsets of a given universe set. Partitions on a set are dual to subsets of a set in the sense of the category-theoretic duality of epimorphisms and monomorphisms--which is reflected in the duality between quotient objects and subobjects throughout algebra. If "propositional" logic is thus seen as the logic of subsets of a universe set, then the question naturally arises of a dual logic of partitions on a universe set. This paper is an introduction to that logic of partitions dual to classical subset logic. The paper goes from basic concepts up through the correctness and completeness theorems for a tableau system of partition logic.

## An Almost Classical Logic for Logic Programming and Nonmonotonic Reasoning

Bry, François
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.65%
The model theory of a first-order logic called N^4 is introduced. N^4 does not eliminate double negations, as classical logic does, but instead reduces fourfold negations. N^4 is very close to classical logic: N^4 has two truth values; implications in N^4 are material, like in classical logic; and negation distributes over compound formulas in N^4 as it does in classical logic. Results suggest that the semantics of normal logic programs is conveniently formalized in N^4: Classical logic Herbrand interpretations generalize straightforwardly to N^4; the classical minimal Herbrand model of a positive logic program coincides with its unique minimal N^4 Herbrand model; the stable models of a normal logic program and its so-called complete minimal N^4 Herbrand models coincide.; Comment: 16 pages. Originally published in proc. PCL 2002, a FLoC workshop; eds. Hendrik Decker, Dina Goldin, Jorgen Villadsen, Toshiharu Waragai (http://floc02.diku.dk/PCL/)

## Implementing Default and Autoepistemic Logics via the Logic of GK

Ji, Jianmin; Strass, Hannes
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.68%
The logic of knowledge and justified assumptions, also known as logic of grounded knowledge (GK), was proposed by Lin and Shoham as a general logic for nonmonotonic reasoning. To date, it has been used to embed in it default logic (propositional case), autoepistemic logic, Turner's logic of universal causation, and general logic programming under stable model semantics. Besides showing the generality of GK as a logic for nonmonotonic reasoning, these embeddings shed light on the relationships among these other logics. In this paper, for the first time, we show how the logic of GK can be embedded into disjunctive logic programming in a polynomial but non-modular translation with new variables. The result can then be used to compute the extension/expansion semantics of default logic, autoepistemic logic and Turner's logic of universal causation by disjunctive ASP solvers such as claspD(-2), DLV, GNT and cmodels.; Comment: Proceedings of the 15th International Workshop on Non-Monotonic Reasoning (NMR 2014)

## On Affine Logic and {\L}ukasiewicz Logic

Arthan, Rob; Oliva, Paulo
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.7%
The multi-valued logic of {\L}ukasiewicz is a substructural logic that has been widely studied and has many interesting properties. It is classical, in the sense that it admits the axiom schema of double negation, [DNE]. However, our understanding of {\L}ukasiewicz logic can be improved by separating its classical and intuitionistic aspects. The intuitionistic aspect of {\L}ukasiewicz logic is captured in an axiom schema, [CWC], which asserts the commutativity of a weak form of conjunction. This is equivalent to a very restricted form of contraction. We show how {\L}ukasiewicz Logic can be viewed both as an extension of classical affine logic with [CWC], or as an extension of what we call \emph{intuitionistic} {\L}ukasiewicz logic with [DNE], intuitionistic {\L}ukasiewicz logic being the extension of intuitionistic affine logic by the schema [CWC]. At first glance, intuitionistic affine logic seems very weak, but, in fact, [CWC] is surprisingly powerful, implying results such as intuitionistic analogues of De Morgan's laws. However the proofs can be very intricate. We present these results using derived connectives to clarify and motivate the proofs and give several applications. We give an analysis of the applicability to these logics of the well-known methods that use negation to translate classical logic into intuitionistic logic. The usual proofs of correctness for these translations make much use of contraction. Nonetheless...

## Characterising equilibrium logic and nested logic programs: Reductions and complexity

Pearce, David; Tompits, Hans; Woltran, Stefan
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.65%
Equilibrium logic is an approach to nonmonotonic reasoning that extends the stable-model and answer-set semantics for logic programs. In particular, it includes the general case of nested logic programs, where arbitrary Boolean combinations are permitted in heads and bodies of rules, as special kinds of theories. In this paper, we present polynomial reductions of the main reasoning tasks associated with equilibrium logic and nested logic programs into quantified propositional logic, an extension of classical propositional logic where quantifications over atomic formulas are permitted. We provide reductions not only for decision problems, but also for the central semantical concepts of equilibrium logic and nested logic programs. In particular, our encodings map a given decision problem into some formula such that the latter is valid precisely in case the former holds. The basic tasks we deal with here are the consistency problem, brave reasoning, and skeptical reasoning. Additionally, we also provide encodings for testing equivalence of theories or programs under different notions of equivalence, viz. ordinary, strong, and uniform equivalence. For all considered reasoning tasks, we analyse their computational complexity and give strict complexity bounds.

## On Spatial Conjunction as Second-Order Logic

Kuncak, Viktor; Rinard, Martin
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.68%
Spatial conjunction is a powerful construct for reasoning about dynamically allocated data structures, as well as concurrent, distributed and mobile computation. While researchers have identified many uses of spatial conjunction, its precise expressive power compared to traditional logical constructs was not previously known. In this paper we establish the expressive power of spatial conjunction. We construct an embedding from first-order logic with spatial conjunction into second-order logic, and more surprisingly, an embedding from full second order logic into first-order logic with spatial conjunction. These embeddings show that the satisfiability of formulas in first-order logic with spatial conjunction is equivalent to the satisfiability of formulas in second-order logic. These results explain the great expressive power of spatial conjunction and can be used to show that adding unrestricted spatial conjunction to a decidable logic leads to an undecidable logic. As one example, we show that adding unrestricted spatial conjunction to two-variable logic leads to undecidability. On the side of decidability, the embedding into second-order logic immediately implies the decidability of first-order logic with a form of spatial conjunction over trees. The embedding into spatial conjunction also has useful consequences: because a restricted form of spatial conjunction in two-variable logic preserves decidability...

## A two-level logic approach to reasoning about computations

Gacek, Andrew; Miller, Dale; Nadathur, Gopalan
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.67%
Relational descriptions have been used in formalizing diverse computational notions, including, for example, operational semantics, typing, and acceptance by non-deterministic machines. We therefore propose a (restricted) logical theory over relations as a language for specifying such notions. Our specification logic is further characterized by an ability to explicitly treat binding in object languages. Once such a logic is fixed, a natural next question is how we might prove theorems about specifications written in it. We propose to use a second logic, called a reasoning logic, for this purpose. A satisfactory reasoning logic should be able to completely encode the specification logic. Associated with the specification logic are various notions of binding: for quantifiers within formulas, for eigenvariables within sequents, and for abstractions within terms. To provide a natural treatment of these aspects, the reasoning logic must encode binding structures as well as their associated notions of scope, free and bound variables, and capture-avoiding substitution. Further, to support arguments about provability, the reasoning logic should possess strong mechanisms for constructing proofs by induction and co-induction. We provide these capabilities here by using a logic called G which represents relations over lambda-terms via definitions of atomic judgments...

## Inconsistency Robustness in Logic Programs

Hewitt, Carl
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.67%
Inconsistency robustness is "information system performance in the face of continually pervasive inconsistencies." A fundamental principle of Inconsistency Robustness is to make contradictions explicit so that arguments for and against propositions can be formalized. This paper explores the role of Inconsistency Robustness in the history and theory of Logic Programs. Robert Kowalski put forward a bold thesis: "Looking back on our early discoveries, I value most the discovery that computation could be subsumed by deduction." However, mathematical logic cannot always infer computational steps because computational systems make use of arbitration for determining which message is processed next by a recipient that is sent multiple messages concurrently. Since reception orders are in general indeterminate, they cannot be inferred from prior information by mathematical logic alone. Therefore mathematical logic cannot in general implement computation. Over the course of history, the term "Functional Program" has grown more precise and technical as the field has matured. "Logic Program" should be on a similar trajectory. Accordingly, "Logic Program" should have a general precise characterization. In the fall of 1972, different characterizations of Logic Programs that have continued to this day: * A Logic Program uses Horn-Clause syntax for forward and backward chaining * Each computational step (according to Actor Model) of a Logic Program is deductively inferred (e.g. in Direct Logic). The above examples are illustrative of how issues of inconsistency robustness have repeatedly arisen in Logic Programs.; Comment: Limits of Classical Logic

## Quantum Logic as Classical Logic

Kramer, Simon
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.66%
We propose a semantic representation of the standard quantum logic QL within a classical, normal modal logic, and this via a lattice-embedding of orthomodular lattices into Boolean algebras with one modal operator. Thus our classical logic is a completion of the quantum logic QL. In other words, we refute Birkhoff and von Neumann's classic thesis that the logic (the formal character) of Quantum Mechanics would be non-classical as well as Putnam's thesis that quantum logic (of his kind) would be the correct logic for propositional inference in general. The propositional logic of Quantum Mechanics is modal but classical, and the correct logic for propositional inference need not have an extroverted quantum character. One normal necessity modality suffices to capture the subjectivity of observation in quantum experiments, and this thanks to its failure to distribute over classical disjunction. The key to our result is the translation of quantum negation as classical negation of observability.; Comment: amplified the first paragraph on Page 3, the paragraph in the middle of Page 5; and the second-last paragraph on Page 9; added Footnote 1 on Page 2, acknowledgements, and references

## Paraconsistent Deontic Logic with Enforceable Rights

Peña, Lorenzo; Ausín, Txetxu
Fonte: Research Studies Press Publicador: Research Studies Press
Tipo: Capítulo de libro Formato: 78723 bytes; application/pdf
ENG
Relevância na Pesquisa
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En: Frontiers of Paraconsistent Logic ed. por D. Batens, Ch. Mortensen, G. Priest & J.-P. van Bendegem Baldford (England): Research Studies Press Ltd. (RSP) [Logic and Computation Series], 2000. ISBN 086302532, pp. 29-47; This paper is devoted to proposing a system of gradualistic (fuzzy) paraconsistent deontic logic, a logic which implements the idea not just of degrees of truth (and falseness) but also that of degrees of obligatoriness and licitness. The system we propose (transitive deontic logic) tries to implement a correct treatment of quantified deontic and juridical propositions, chiefly those concerning positive rights, which are couched in terms of existential quantifiers (the right to have a dwelling, a job, to enjoy medical care and so on). Even negative rights are expressed through universal quantifiers. Thus, without an adequate treatment of quantifiers, no system of deontic logic is satisfactory. However, standard systems of deontic logic make it extremely difficult, if not downright impossible, to implement quantifiers in any reasonable way. In order to achieve such a treatment, new postulates are put forward, but at the same time most of the usual axioms of standard systems of deontic logic are dropped. In fact...

## Logic and Ontology; Logic and Ontology

da Costa, Newton Carneiro Affonso; Universidade de São Paulo
Fonte: Federal University of Santa Catarina – UFSC Publicador: Federal University of Santa Catarina – UFSC
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf