A generalization of Reiter's default logic is proposed that provides an improved treat ment of default reasoning with disjunctive in formation. The new system --- the disjunctive default logic --- is used in the paper to reex amine the ``broken-hand'' example of Poole. We also compare the expressive power of this approach with two other approaches which interpret disjunctive information within the standard default logic. Finally, we show that our semantics of disjunctive default logic is a generalization of the semantics of disjunctive and extended disjunctive databases.

PS

In Allen, James and Fikes, Richard and Sandewall, Erik, editors, Proceedings of International Conference on Principles of Knowledge Representation and Reasoning (KR), 230-237, 1991.

@INPROCEEDINGS{gel91a, title={Disjunctive Defaults}, author={Michael Gelfond and Vladimir Lifschitz and Halina Przymusinska and Miroslaw Truszczynski}, booktitle={Proceedings of International Conference on Principles of Knowledge Representation and Reasoning (KR)}, editor={Allen, James and Fikes and Richard and Sandewall and Erik}, pages={230-237}, url="http://www.cs.utexas.edu/users/ai-lab/?gel91a", year={1991} }