{"type":"ScholarlyArticle","title":"Constructive Tightly Grounded Autoepistemic Reasoning","authors":[{"name":"Ilkka Niemelä","slug":"ilkka-niemela","given":"Ilkka","family":"Niemelä","affiliation":""}],"abstract":"The k~y concept of autoepistemic logic introduced by Moore is a stable expansion of a set of premises, i.e., a set of beliefs adopted by an agent with perfect introspection capabilities on the basis of the premises. Moore's formalization of a stable expansion, however, is nonconstructive and produces sets of beliefs which are quite weakly grounded in the premises. A new more constructive definition of the sets of beliefs of the agent is proposed. It is based on classical logic and enumerations of formulae. Considering only a certain subclass of enumerations, L-h.ierarchic enumerations, an attractive class of expansions is captured to characterize the sets of beliefs of a fully introspective agent. These L-hierarchic expansions are stable set minimal, very tightly grounded in the premises and independent of the syntactic representation of premises. Furthermore, Reiter's default logic is shown to be a special case of autoepistemic logic based on L-hierarchic expansions.","doi":null,"url":"https://ijcai.org/proceedings/1991/60","pdf":"https://ijcai.org/proceedings/1991/0060.pdf","markdown":"https://ijcai.org/proceedings/1991/60.md","bibtex":"https://ijcai.org/proceedings/1991/bibtex/60","volume":{"slug":"1991","title":"Proceedings of the Twelfth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 1991","url":"https://ijcai.org/proceedings/1991/","year":1991,"location":"Sydney, New South Wales, Australia","dates":"24-30 August 1991","editors":"John Mylopoulos and Ray Reiter","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Knowledge Representation","track":"Knowledge Representation","number":60,"pages":{"first":399,"last":404},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}