Modular Paracoherent Answer Sets

Giovanni Amendola, Thomas Eiter, Nicola Leone

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The answer set semantics may assign a logic program no model due to classic contradiction or cyclic negation. The latter can be remedied by resorting to a paracoherent semantics given by semi-equilibrium (SEQ) models, which are 3-valued interpretations that generalize the logical reconstruction of answer sets given by equilibrium models. While SEQ-models have interesting properties, they miss modularity in the rules, such that a natural modular (bottom up) evaluation of programs is hindered. We thus refine SEQ-models using splitting sets, the major tool for modularity in modeling and evaluating answer set programs. We consider canonical models that are independent of any particular splitting sequence from a class of splitting sequences, and present two such classes whose members are efficiently recognizable. Splitting SEQ-models does not make reasoning harder, except for deciding model existence in presence of constraints (without constraints, split SEQ-models always exist).
Original languageEnglish
Title of host publicationLogics in Artificial Intelligence - 14th European Conference, JELIA 2014, Funchal, Madeira, Portugal, September 24-26, 2014. Proceedings
PublisherSpringer, Cham
Number of pages15
ISBN (Electronic)978-3-319-11558-0
ISBN (Print)978-3-319-11557-3
Publication statusPublished - 2014

Publication series

NameLecture Notes in Computer Science
PublisherSpringer, Cham
ISSN (Print)0302-9743


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