Contradiction: When avoidance equals removal Part I

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5 Citations (Scopus)


Recently several authors have stressed and illustrated the importance of including a second kind of negation (explicit negation) in logic programs besides “negation as failure”, and its use in deductive databases, knowledge representation, and nonmonotonic reasoning. By introducing explicit negation into logic programs contradiction may appear. In this work we present two approaches for dealing with contradiction, and show their equivalence. One of the approaches consists in avoiding contradiction, and is based on restrictions in the adoption of abductive hypotheses. The other approach consists in removing contradiction, and is based on a transformation of contradictory programs into noncontradictory ones, guided by the reasons for contradiction. The work is divided into two parts: one is presented in this paper, and comprises the contradiction avoidance approach, and the other in [16] in this volume, comprises the contradiction removal approach and shows the equivalence between the avoidance and removal approaches.

Original languageEnglish
Title of host publicationExtensions of Logic Programming - 4th International Workshop, ELP 1993, Proceedings
EditorsRoy Dyckhoff
Place of PublicationBerlin, Heidelberg
Number of pages13
ISBN (Electronic)978-3-540-48417-2
ISBN (Print)978-3-540-58025-6
Publication statusPublished - 1994
Event4th International Workshop on Extensions of Logic Programming, ELP 1993 - St Andrews, United Kingdom
Duration: 29 Mar 19931 Apr 1993

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume798 LNAI
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference4th International Workshop on Extensions of Logic Programming, ELP 1993
Country/TerritoryUnited Kingdom
CitySt Andrews


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