ECAI-2002 Conference Paper

[full paper]

Uncontroversial Default Logic

Paolo Liberatore

Many variants of default logics exist. Two of the main differences among them are the choice between local or global consistency and the choice of accepting maximally successful sets of defaults. Proving a result that is valid in all variants amounts to showing either a proof that holds for all semantics or a different proof for each semantics. In this paper, we characterize theories that do not depend at all on what makes the semantics different. A result that is proved on such theories holds not only for all considered semantics, but also on any other semantics that differs on the classical one because of the two choices. These theories are also of interest for practical applications of default logic, as an implemented system should be able to detect (for example, to warn the user) any theory whose semantics is debatable.

Keywords: Nonmonotonic Reasoning, Knowledge Representation

Citation: Paolo Liberatore: Uncontroversial Default Logic. In F. van Harmelen (ed.): ECAI2002, Proceedings of the 15th European Conference on Artificial Intelligence, IOS Press, Amsterdam, 2002, pp.526-530.