A semantics for open normal defaults via a modified preferential approach

  • Franz Baader
  • Karl Schlechta
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 747)


We present a new approach for handling open normal defaults that makes it possible
  1. 1.

    to derive existentially quantified formulae from other existentially quantified formulae by default,

  2. 2.

    to derive universally quantified formulae by default, and

  3. 3.

    to treat cardinality formulae analogously to other formulae.


Differing from previous approaches that do not satisfy all these properties, we will not view open defaults as schemata for certain instantiated defaults. Instead they will be used to define a preference relation on models. In modification of the usual approaches to preferential semantics we shall consider limits instead of minimal models.


Preference Relation Minimal Model Default Rule Default Theory Ground Term 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • Franz Baader
    • 1
  • Karl Schlechta
    • 2
  1. 1.Lehr- und Forschungsgebiet Theoretische InformatikRWTH AachenAachen
  2. 2.Université de ProvenceMarseille Cedex 3

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