1999/01/28 by Victor Marek, Victor W. Marek, Marek, Victor +5
Computer Science · #Artificial Intelligence (cs.AI) #F.4.1 #FOS: Computer and information sciences #I.2.3 #I.2.4 #Logic in Computer Science (cs.LO) #Logic, Reasoning, and Knowledge #cs.AI #cs.LO
paper · pdf · doi:10.48550/arxiv.cs/9901016
Annals of Mathematics and Artificial Intelligence, 21 (1997), pp. 343-358
arxiv created 1999/01/28 · openalex publication_date 1999/01/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Default logic can be regarded as a mechanism to represent families of belief sets of a reasoning agent. As such, it is inherently second-order. In this paper, we study the problem of representability of a family of theories as the set of extensions of a default theory. We give a complete solution to the representability by means of normal default theories. We obtain partial results on representability by arbitrary default theories. We construct examples of denumerable families of non-including theories that are not representable. We also study the concept of equivalence between default theories.