http://biblioteca.universia.net/searchAutor.do?q=Maher,%20Michael%20J. Resultados 1 - 10 de 135 de Maher, Michael J.. (0,12 segundos) es http://biblioteca.universia.net/img/logotipo.jpg http://biblioteca.universia.net/ http://biblioteca.universia.net/ficha.do?id=46911893 It has been conjectured [Blair] that every definite clause logic program containing exactly one rule is canonical. This note presents a simple proof of this conjecture. Michael Maher Ibm; Michael J. Maher http://biblioteca.universia.net/ficha.do?id=242860 Defeasible logic is an efficient logic for defeasible reasoning. It is defined through a proof theory and, until now, has had no model theory. In this paper a model-theoretic semantics is given for defeasible logic. The logic is sound and complete with respect to the semantics. We also briefly outline how this approach extends to a wide range of defeasible logics. Maher, Michael J. http://biblioteca.universia.net/ficha.do?id=562531 Defeasible logic is a rule-based nonmonotonic logic, with both strict and defeasible rules, and a priority relation on rules. We show that inference in the propositional form of the logic can be performed in linear time. This contrasts markedly with most other propositional nonmonotonic logics, in which inference is intractable. Maher, Michael J. http://biblioteca.universia.net/ficha.do?id=41843119 We address the problem of lifting definitions, results, and even proofs for the theory of logic programming, so that they apply to constraint logic programming (CLP). We attempt to systematize this lifting, where it is possible, and delineate where it is not possible. We show that the Independence of Negated Constraints property of constraint domains is fundamental to several different aspects of constraint logic programming. This is a principal cause for the inability to lift some traditiona... Michael J. Maher http://biblioteca.universia.net/ficha.do?id=41843762 . We address the problem of determining those constraint domains A for which the traditional logic programming semantics and the constraint logic programming semantics CLP (A) coincide. This reduces to a study of non-standard models of Clark's axioms and the notion of solution compactness introduced in the CLP scheme. The results of this study include the proof of the existence of a free product in the class of algebras defined by Clark's axioms, a characterization of when Clark's axioms form... Michael J. Maher http://biblioteca.universia.net/ficha.do?id=41846941 We extend the notions of functional and finiteness dependencies to apply to subsets of a relation that are specified by constraints. These dependencies have many applications. We are able to characterize those constraint domains which admit a polynomial time solution of the implication problem (assuming P/=NP) and give an efficient algorithm for these cases, modulo the cost of constraint manipulation. For other cases we offer approximate algorithms. Finally, we outline some applications of th... Michael J. Maher http://biblioteca.universia.net/ficha.do?id=41846999 The well-founded semantics and stable model semantics have proven popular semantics for logic programs. However, these semantics (and others) are not directly amenable to logical reasoning since logically equivalent logic programs may have different stable or well-founded models. Many natural simplifications are not universally valid. Furthermore, in some semantics -- including the stable model semantics -- the definition of a new predicate in terms of old predicates can affect the semantics ... Michael J. Maher http://biblioteca.universia.net/ficha.do?id=41848754 this paper our aim is to adapt and apply methods of giving semantics to non-monotonic rule systems to the purpose of making new definitions in an unestablished area. Inasmuch as we maximize predicate extensions and have different motivations from non-monotonic reasoning, this work can serve as a guiding example in the development of more abstract notions of non-monotonic rule systems, as begun in [19]. Michael J. Maher http://biblioteca.universia.net/ficha.do?id=41849527 Constraints are predefined relations with a special implementation mechanism. Logic formalisms provide specific reasoning facilities. We look at the effect of adding constraints to existing logic-based executable formalisms, focussing on the semantics of the combined formalisms. We find that in cases where this has been successful the operations of the formalism can be formulated logically and then extended easily to constraints. In many cases a disjunctive property of the constraints is refl... Michael J. Maher http://biblioteca.universia.net/ficha.do?id=42030963 It has been conjectured [Blair] that every definite clause logic program containing exactly one rule is canonical. This note presents a simple proof of this conjecture. Michael J. Maher