A Default Logic Patch for Default Logic

Philippe Besnard (1, 2) , Éric Grégoire (3) , Sébastien Ramon (3)

1 IRIT-LILaC - Logique, Interaction, Langue et Calcul
2 CNRS - Centre National de la Recherche Scientifique
3 CRIL - Centre de Recherche en Informatique de Lens

This paper is about the fusion of multiple information sources represented using default logic. More precisely, the focus is on solving the problem that occurs when the standard-logic knowledge parts of the sources are contradictory, as default theories trivialize in this case. To overcome this problem, it is shown that replacing each formula belonging to Minimally Unsatisfiable Subformulas by a corresponding supernormal default allows appealing features. Moreover, it is investigated how these additional defaults interact with the initial defaults of the theory. Interestingly, this approach allows us to handle the problem of default theories containing inconsistent standard-logic knowledge, using the default logic framework itself.

Domaines: Intelligence artificielle [cs.AI]

Philippe Besnard, Éric Grégoire, Sébastien Ramon. A Default Logic Patch for Default Logic. 10th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU'09), 2009, Verona, Italy. pp.578-589. ⟨hal-00866491⟩