{"type":"ScholarlyArticle","title":"Efficient Reasoning in Proper Knowledge Bases with Unknown Individuals","authors":[{"name":"Giuseppe De Giacomo","slug":"giuseppe-de-giacomo","given":"Giuseppe","family":"De Giacomo","affiliation":""},{"name":"Yves Lespérance","slug":"yves-lesperance","given":"Yves","family":"Lespérance","affiliation":""},{"name":"Hector J. Levesque","slug":"hector-j-levesque","given":"Hector J.","family":"Levesque","affiliation":""}],"abstract":"This work develops an approach to efficient reasoning in first-order knowledge bases with incomplete information. We build on Levesque's proper knowledge bases approach, which supports limited incomplete knowledge in the form of a possibly infinite set of positive or negative ground facts. We propose a generalization which allows these facts to involve unknown individuals, as in the work on labeled null values in databases. Dealing with such unknown individuals has been shown to be a key feature in the database literature on data integration and data exchange. In this way, we obtain one of the most expressive first-order open-world settings for which reasoning can still be done efficiently by evaluation, as in relational databases. We show the soundness of the reasoning procedure and its completeness for queries in a certain normal form.","doi":"10.5591/978-1-57735-516-8/IJCAI11-144","url":"https://ijcai.org/proceedings/2011/144","pdf":"https://ijcai.org/proceedings/2011/0144.pdf","markdown":"https://ijcai.org/proceedings/2011/144.md","bibtex":"https://ijcai.org/proceedings/2011/bibtex/144","volume":{"slug":"2011","title":"Proceedings of the Twenty-Second International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2011","url":"https://ijcai.org/proceedings/2011/","year":2011,"location":"Barcelona, Catalonia, Spain","dates":"16–22 July 2011","editors":"Toby Walsh","isbn":"978-1-57735-512-0; 978-1-57735-513-7; 978-1-57735-514-4; 978-1-57735-515-1; 978-1-57735-516-8","publisher":"AAAI Press/International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":null,"track":"","number":144,"pages":{"first":827,"last":831},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}