Conditional logics of normality as modal systems
Craig E. Boutilier · 1990
Recently, conditional logics have been developed for ap-plication to problems in default reasoning. We present a uniform framework for the development and investi-gation of conditional logics to represent and reason with “normality”, and demonstrate these logics to be equiv-alent to extensions of the modal system S4. We also show that two conditional logics, recently proposed to reason with default knowledge, are equivalent to frag-ments of two logics developed in this framework.