Unrestricted preferential structures
One of the major open problems of preferential structures was perhaps to give an unrestricted representation result. We give a solution to the problem in this short, technical paper. Up to now-to the author's knowledge-all representation results for preferential structures were subject to some restriction: definability preservation (the author's terminology, fullness in Lehmann's terminology) or some kind of finiteness. The results presented here are valid without any restrictions.
definability nonmonotonic logic preferential models common sense reasoning