201.
The Weighting Issue in Fuzzy Logic
- Xudong Luo; Chengqi Zhang; J. Cai; Jingqiu Cai
this paper is to establish a class of models for solving the weight problem in fuzzy logic. First, some constraints that weighted fuzzy logic should satisfy are given based on Triangular norms and conorms. Then, based on these constraints, a class of models (referred to as relative weighted models) are established for handling weights in fuzzy logic. These models are novel in three aspects: (1) they include non-weighted models as their special cases, (2) the weighted conjunction and weighted disjunction can be distinguished from each other, and (3) the information from all sub-propositions can be sufficiently considered. In addition, this...
202.
Executing Suspended Logic Programs
- Robert Kowalski; Francesca Toni; Gerhard Wetzel
. We present an extension of Logic Programming (LP) which, in addition to ordinary LP clauses, also includes integrity constraints, explicit representation of disjunction in the bodies of clauses and in goals, and suspension of atoms as in concurrent logic languages. The resulting framework aims to unify Constraint Logic Programming (CLP), Abductive Logic Programming (ALP) and Semantic Query Optimisation (SQO) in deductive databases. We present a proof procedure for the new framework, simplifying and generalising previously proposed proof procedures for ALP. We discuss applications of the framework, formulating traditional problems from LP, ALP, CLP and SQO. Keywords: Logic Programming (LP),...
203.
Lógica borrosa y decisiones judiciales: el peligro de una falacia racionalista
- Mazzarese, Tecla
Traducción castellana de José Juan Moreso del original, Tecla Mazzarese: Fuzzy Logic and Judicial Decision-Making: The Peril of a Rationalist Fallacy. Texto de la ponencia presentada por la autora en el Congreso de Filosofía del Derecho en Homenaje al Prof. Ernesto Garzón Valdés, celebrado en Vaquerías
(Córdoba-Argentina) en septiembre de 1992.
204.
Monad-independent dynamic logic in HasCasl
- Lutz Schröder; Till Mossakowski
Monads have been recognized by Moggi as an elegant device for dealing with stateful computation in functional programming languages. In previous work, we have introduced a Hoare calculus for partial correctness of monadic programs. All this has been done in an entirely monad-independent way. Here, we extend this to a monad-independent dynamic logic (assuming a moderate amount of additional infrastructure for the monad). Dynamic logic is more expressive than the Hoare calculus; in particular, it allows reasoning about termination and total correctness. As the background formalism for these concepts, we use the logic of HasCasl, a higher-order language for functional...
205.
Combining Logic Programming and Equation Solving
- Steffen Hölldobler
Conditional equational theories can be built into logic programming using a generalized resolution rule which calls a universal unification procedure. Such unification procedures are often defined by sound and strongly complete sets of inference rules.
206.
Probabilistic Logic under Coherence: Complexity and Algorithms
- Veronica Biazzo; Angelo Gilio; Thomas Lukasiewicz
We study probabilistic logic under the viewpoint of the coherence principle of de Finetti. In detail, we explore the relationship between coherence-based and classical modeltheoretic probabilistic logic. Interestingly, we show that the notions of g-coherence and of g-coherent entailment can be expressed by combining notions in model-theoretic probabilistic logic with concepts from default reasoning. Using these results, we analyze the computational complexity of probabilistic reasoning under coherence. Moreover, we present new algorithms for deciding g-coherence and for computing tight g-coherent intervals, which reduce these tasks to standard reasoning tasks in model-theoretic probabilistic logic. Thus, efficient techniques for model-theoretic probabilistic reasoning...
207.
Structural Cut Elimination in Linear Logic
- Frank Pfenning December; Frank Pfenning
We present a new proof of cut elimination for linear logic which proceeds by three nested structural inductions, avoiding the explicit use of multi-sets and termination measures on sequent derivations. The computational content of this proof is a non-deterministic algorithm for cut elimination which is amenable to an elegant implementation in Elf. We show this implementation in detail. This work was supported by NSF Grant CCR-9303383 The views and conclusions contained in this document are those of the author and should not be interpreted as representing the official policies, either expressed or implied, of NSF or the U.S. government. Keywords:...
208.
Some Semantical Aspects of Linear Logic
- Andreas Blass Mathematics
We describe and discuss several semantical views of linear logic. Our primary topic is game semantics, including modifications suggested by Abramsky, Jagadeesan, Hyland, Ong, and Japaridze. We also briefly discuss Girard's coherence spaces and de Paiva's Dialectica-like semantics. 1 Keywords: linear logic, semantics, games, determinacy 1 Introduction The WoLLIC talk on which this paper is based consisted of some introductory material on linear logic and several observations about its semantics, with particular emphasis on game semantics. In this paper, I shall not repeat all the introductory material, because it is available in Girard's original paper on the subject [12] or...
209.
Loop Checks for Logic Programs with Functions
- Yi-Dong Shen; Li-yan Yuan; Jia-huai You
Two complete loop checking mechanisms have been presented in the literature for logic programs with functions: OS-check and EVA-check. OS-check is computationally ecient but quite unreliable in that it often mis-identies innite loops, whereas EVA-check is reliable for a majority of cases but quite expensive. In this paper, we develop a series of new complete loop checking mechanisms, called VAFchecks. The key technique we introduce is the notion of expanded variants, which captures a key structural characteristic of innite loops. We show that our approach is superior to both OS-check and EVA-check in that it is as ecient as OS-check...
210.
Principle for Semantics of Dynamic Logic Programming
- José Júlio Alferes; Federico Banti; Antonio Brogi; João Alexandre Leite
Abstract. Over recent years, various semantics have been proposed for dealing with updates in the setting of logic programs. The availability of different semantics naturally raises the question of which are most adequate to model updates. A systematic approach to face this question is to identify general principles against which such semantics could be evaluated. In this paper we motivate and introduce a new such principle – the refined extension principle. Such principle is complied with by the stable model semantics for (single) logic programs. It turns out that none of the existing semantics for logic program updates, even though...
211.
Monad-independent dynamic logic in HasCasl
- Lutz Schröder; Till Mossakowski
Monads have been recognized by Moggi as an elegant device for dealing with stateful computation in functional programming languages. In previous work, we have introduced a Hoare calculus for partial correctness of monadic programs. All this has been done in an entirely monad-independent way. Here, we extend this to a monad-independent dynamic logic (assuming a moderate amount of additional infrastructure for the monad). Dynamic logic is more expressive than the Hoare calculus; in particular, it allows reasoning about termination and total correctness. As the background formalism for these concepts, we use the logic of HasCasl, a higher-order language for functional...
212.
Monad-independent dynamic logic in HasCASL
- Till Mossakowski; Lutz Schröder; Lutz Schröder
Monads have been recognized by Moggi as an elegant device for dealing with stateful computation in functional programming languages. In previous work, we have introduced a Hoare calculus for partial correctness of monadic programs. All this has been done in an entirely monad-independent way. Here, we extend this to a monad-independent dynamic logic (assuming a moderate amount of additional infrastructure for the monad). Dynamic logic is more expressive than the Hoare calculus; in particular, it allows reasoning about termination and total correctness. The background formalism for these concepts is the logic of HasCasl, a higher-order language for functional specification and...
213.
Using Stochastic Solvers in Constraint Logic Programming
- Peter J. Stuckey; Vincent W. L. Tam
This paper proposes a general framework for integrating a constraint logic programming system with a stochastic constraint solver to solve constraint satisfaction problems efficiently. Stochastic solvers can solve hard constraint satisfaction problems very efficiently, and constraint logic programming allows heuristics and problem breakdown to be encoded in the same language as the constraints. Hence their combination is attractive. Unfortunately there is a mismatch in the kinds of information a stochastic solver provides, and that which a constraint logic programming system requires. We study the semantic properties of constraint logic programming systems that make use of stochastic solvers, and give soundness...
214.
Observational Logic
- Observational Logic; Ecole Normale; Suprieure Cachan; Rolf Hennicker; Michel Bidoit
. We present an institution of observational logic which generalizes earlier approaches to observational systems specification in various ways. First, we introduce a notion of an observational signature which incorporates the declaration of a distinguished set of observers. Then, we define observational algebras whose operations are required to be compatible with the indistinguishability relation determined by the observers of an observational signature. In particular, we introduce a homomorphism concept for observational algebras which adequately expresses observational relationships between algebras. Then we consider a flexible notion of observational signature morphism which guarantees the satisfaction condition of institutions w.r.t. observational satisfaction for...
215.
Lógica y conocimiento
- Tejeda Moreno, V. Antonio
216.
El atomismo lógico
- Russell, Bertrand
217.
Hoare Logic, Executable Specifications, and Logic Programs
- Norbert E. Fuchs
this paper, I present a new method that is based on non-executable logic
specifications derived from Hoare correctness formulae for logic programs. Logic
specifications specify the same programs, they are equivalent to correctness formulae.
2
218.
The Limits of Horn Logic Programs 1
- Shilong Ma; Yuefei Sui; Ke Xu
Abstract: Given a sequence {Πn} of Horn logic programs, the limit Π of {Πn} is the set of the clauses such that every clause in Π belongs to almost every Πn and every clause in infinitely many Πn’s belongs to Π also. The limit program Π is still Horn but may be infinite. In this paper, we consider if the least Herbrand model of the limit of a given Horn logic program sequence {Πn} equals the limit of the least Herbrand models of each logic program Πn. It is proved that this property is not true in general but holds...
219.
Description Logic Programs: Combining Logic Programs with Description Logic
- Benjamin N. Grosof,Ian Horrocks
We show how to interoperate, semantically and inferentially, between
the leading Semantic Web approaches to rules (RuleML
Logic Programs) and ontologies (OWL/DAML+OIL Description
Logic) via analyzing their expressive intersection. To do so, we define
a new intermediate knowledge representation (KR) contained
within this intersection: Description Logic Programs (DLP), and
the closely related Description Horn Logic (DHL) which is an expressive
fragment of first-order logic (FOL). DLP provides a significant
degree of expressiveness, substantially greater than the RDFSchema
fragment of Description Logic.
220.
Constructor-based Observational Logic ⋆
- Observational Logic; Michel Bidoit A; Rolf Hennicker B
This paper focuses on the integration of reachability and observability concepts within an algebraic, institution-based framework. In the first part of this work, we develop the essential ingredients that are needed to define the constructorbased observational logic institution, called COL, which takes into account both the generation- and observation-oriented aspects of software systems. The underlying paradigm of our approach is that the semantics of a specification should be as loose as possible to capture all its correct realizations. We also consider the “black box ” semantics of a specification which is useful to study the behavioral properties a user can...
