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Reasoning with maximal time intervals

  • Cristina Ribeiro
  • António Porto
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 567)

Abstract

The ability to deal with partial knowledge is particularly important in a temporal domain. We describe a temporal language that accounts for incompletely specified temporal information about propositions. Temporal terms in the language denote time instants and inequality constraints are used to keep incomplete information about their order. The language is semantically based on the notion of maximal interval, the denotation of a proposition being a set of maximal intervals where it holds. The adequacy of maximal intervals for temporal knowledge representation has been justified elsewhere [5]. In a partial KB, abduction on the temporal order is generally needed to answer a query, and the answer is then conditional on the abduced facts. To comply with the intended semantics, an implicit form of temporal consistency has to be enforced, and this presents the main challenge to the design of the inference mechanism. We present here the syntax and declarative semantics of a propositional version of the language of maximal intervals and a first discussion of the problems in designing an inference system adequate to work with this temporal framework. Rather than presenting a complete solution, we discuss several approaches.

Keywords

knowledge representation temporal reasoning deductive databases 

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References

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    Drew McDermott. A Temporal Logic for Reasoning About Processes and Plans. Cognitive Science, (6):101–155, 1982.CrossRefGoogle Scholar
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    António Porto and Cristina Ribeiro. Maximal Intervals: A Logic of Temporal Information. Technical Report DI-28, Departamento de Informática, FCT-UNL, 1990.Google Scholar
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    Marek Sergot. Personal communication, 1991.Google Scholar
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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • Cristina Ribeiro
    • 1
  • António Porto
    • 1
  1. 1.Departamento de InformáticaUniversidade Nova de LisboaMonte da CaparicaPortugal

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