A study of provability in defeasible logic
Defeasible logic is a logic-programming based nonmonotonic reasoning formalism which has an efficient implementation. It makes use of facts, strict rules, defeasible rules, defeaters, and a superiority relation. We clarify the proof theory of defeasible logic through an analysis of the conclusions it can draw. Using it, we show that defeaters do not add to the expressiveness of defeasible logic, among other results. The analysis also supports the restriction of defeasible logic to admit only acyclic superiority relations.
KeywordsLogic Program Proof Theory Strict Rule Default Theory Nonmonotonic Reasoning
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- 1.G. Antoniou. Nonmonotonic Reasoning. MIT Press 1997.Google Scholar
- 2.G. Antoniou, D. Billington and M.J. Maher. Normal Forms for Defeasible Logic. In Proc. Joint International Conference and Symposium on Logic Programming 1998, MIT Press 1998 (accepted).Google Scholar
- 4.M.A. Covington, D. Nute and A. Vellino. Prolog Programming in Depth. Prentice Hall 1997.Google Scholar
- 5.B.N. Grosof. Prioritized Conflict Handling for Logic Programs. In: Proc. Int. Logic Programming Symposium, J. Maluszynski (Ed.), 197–211. MIT Press, 1997.Google Scholar
- 6.V. Marek and M. Truszczynski. Nonmonotonic Logic, Springer 1993.Google Scholar
- 7.D. Nute. Defeasible Reasoning. In Proc. 20th Hawaii International Conference on Systems Science, IEEE press 1987, 470–477.Google Scholar
- 8.D. Nute. Defeasible Logic. In D.M. Gabbay, C.J. Hogger and J.A. Robinson (eds.): Handbook of Logic in Artificial Intelligence and Logic Programming Vol. 3, Oxford University Press 1994, 353–395.Google Scholar