The mathematics of non-monotonic reasoning

摘要

Part I of this memo discusses minimal entailment and minimal completion suggested by McCarthy (now included in his more general notion of circumscription) and Part II discusses the “non-monotonic logic” of McDermott and Doyle. McCarthy attempts to capture an idea inherent in Occam's razor: only those objects should be assumed to exist which are minimally required by the context. McDermott and Doyle approach the problem by discussing provability as a modality.