Hypothetical updates, priority and inconsistency in a logic programming language

  • D. Gabbay
  • L. Giordano
  • A. Martelli
  • N. Olivetti
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 928)


In this paper we propose a logic programming language which supports hypothetical updates together with integrity constraints. The language allows sequences of updates by sets of atoms and it makes use of a revision mechanism to restore consistency when an update violates some integrity constraint. The revision policy we adopt is based on the simple idea that more recent information is preferred to earlier one. This language can be used to perform several types of defeasible reasoning. We define a goal-directed proof procedure for the language and develope a logical characterization in a modal logic by introducing an abductive semantics.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • D. Gabbay
    • 1
  • L. Giordano
    • 2
  • A. Martelli
    • 2
  • N. Olivetti
    • 2
  1. 1.Department of ComputingImperial CollegeLondonUK
  2. 2.Dipartimento di InformaticaUniversità di TorinoTorinoItaly

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