this paper presents a debugger for Prolog ‘PROEDIT2’, In order to express the complex execution mechanism of Prolog, a new execution model for Prolog ‘BPM’ is also proposed. PROEDIT2 shows the execution of Prolog ...
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Two related algorithms for implementing parallel n-bit binary addition and evaluating n-th degree polynomials, respectively, are presented. the approach taken makes use of an iterative construction, the computation tr...
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Two related algorithms for implementing parallel n-bit binary addition and evaluating n-th degree polynomials, respectively, are presented. the approach taken makes use of an iterative construction, the computation tree. the algorithms are particularly effective for moderate values of n and are in accord with well-known asymptotic bounds. In the case of n-bit addition, the implementations constitute lookahead tree circuits of r-input standard logic elements. Extensions to modular tree structures for lookahead adders are also considered. In the case of parallel polynomial evaluation, the operations of ordinary addition and multiplication are assumed withthe capability to employ r arguments simultaneously.
Hybridisation is a systematic process along which the characteristic features of hybrid logic, both at the syntactic and the semantic levels, are developed on top of an arbitrary logic framed as an institution. In a s...
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Hybridisation is a systematic process along which the characteristic features of hybrid logic, both at the syntactic and the semantic levels, are developed on top of an arbitrary logic framed as an institution. In a series of papers this process has been detailed and taken as a basis for a specification methodology for reconfigurable systems. the present paper extends this work by showing how a proof calculus (in both a Hilbert and a tableau based format) for the hybridised version of a logic can be systematically generated from a proof calculus for the latter. Such developments provide the basis for a complete proof theory for hybrid(ised) logics, and thus pave the way to the development of (dedicated) proof support. (C) 2016 Elsevier B.V. All rights reserved.
In this paper we introduce revision programming - a logic-based framework for describing constraints on databases and providing a computational mechanism to enforce them. Revision programming captures those constraint...
In this paper we introduce revision programming - a logic-based framework for describing constraints on databases and providing a computational mechanism to enforce them. Revision programming captures those constraints that can be stated in terms of the membership (presence or absence) of items (records) in a database. Each such constraint is represented by a revision rule alpha <-- alpha(1),...,alpha(k), where alpha and all alpha(i) are of the form in(a) and out(b). Collections of revision rules form revision programs. Similarly as logic programs, revision programs admit both declarative and imperative (procedural) interpretations. In our paper, we introduce a semantics that reflects both interpretations. Given a revision program, this semantics assigns to any database B a collection (possibly empty) of P-justified revisions of B. the paper contains a thorough study of revision programming. We exhibit several fundamental properties of revision programming. We study the relationship of revision programming to logicprogramming. We investigate complexity of reasoning with revision programs as well as algorithms to compute P-justified revisions. Most importantly from the practical database perspective, we identify two classes of revision programs, safe and stratified, with a desirable property that they determine for each initial database a unique revision.
Recently there has been increased interest in logicprogramming-based default reasoning approaches which are not using negation-as-failure in their object language. Instead, default reasoning is modelled by rules and ...
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ISBN:
(纸本)3540667490
Recently there has been increased interest in logicprogramming-based default reasoning approaches which are not using negation-as-failure in their object language. Instead, default reasoning is modelled by rules and a priority relation among them. Historically the first logic in this class was Defeasible logic. In this paper we will study its relationship to other approaches which also rely on the idea of using logic rules and priorities. In particular we will study sceptical LPwNF, courteous logic programs, and priority logic.
In this paper, we consider the problem of scheduling n jobs in an m-machine permutation flowshop with time lags between consecutive operations of each job. the processing order of jobs is the same for each machine. th...
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ISBN:
(纸本)9781467358149;9781467358125
In this paper, we consider the problem of scheduling n jobs in an m-machine permutation flowshop with time lags between consecutive operations of each job. the processing order of jobs is the same for each machine. the time lag is defined as the waiting time between consecutive operations. We use square logic-based Benders decomposition to minimize the total number of tardy jobs with long time horizon defined on the last machine. We combine Mixed Integer Linear programming (MILP) to allocate jobs to time intervals of the time horizon and scheduled using Constraint programming (CP). Also, a lower bound based on Moore's algorithm is developed. then, computational results are reported.
We introduce a constraint system called FT. this system offers a theoretical and practical alternative to the usual Herbrand system of constraints over constructor trees. Like Herbrand, FT provides a universal data st...
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We introduce a constraint system called FT. this system offers a theoretical and practical alternative to the usual Herbrand system of constraints over constructor trees. Like Herbrand, FT provides a universal data structure based on trees. However, the trees of FT (called feature trees) are more general than the constructor trees of Herbrand, and the constraints of FT are of finer grain and of different expressiveness. the essential novelty of FT is provided by functional attributes called features which allow representing data as extensible records, a more flexible way than that offered by Herbrand's fixed arity constructors. the feature tree structure determines an algebraic semantics for FT. We establish a logical semantics, thanks to three axiom schemes presenting the first-order theory FT. We propose using FT as a constraint system for logicprogramming. We provide a test for constraint unsatisfiability, and a test for constraint entailment. the former corresponds to unification and the latter to matching. the combination of the two is needed for advanced control mechanisms. We use the concept of relative simplification of constraints, a normalization process that decides entailment and unsatisfiability simultaneously. the two major technical contributions of this work are: (i) an incremental system performing relative simplification for FT that we prove to be sound and complete;and (ii) a proof showing that FT satisfies independence of negative constraints, the property that conjoined negative constraints may be handled independently.
logicprogramming is a prominent approach for knowledge representation and reasoning. Answer set semantics of logic. programs provides a promising constraint programming paradigm. Consistency is a significant issue in...
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ISBN:
(纸本)9780769533056
logicprogramming is a prominent approach for knowledge representation and reasoning. Answer set semantics of logic. programs provides a promising constraint programming paradigm. Consistency is a significant issue in answer set programming. We investigated the order consistent logic programs and showed that the class of order consistent logic programs is identical to the call consistent one for finite logic programs, order consistency is decidable in polynomial time and Lifschitz's order consistency is identical to Sato's definition.
A parser formalism for natural languages that is so restricted as to rule out the definition of linguistic structures that do not occur in any natural language can make the task of grammar construction easier, whether...
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