{"type":"ScholarlyArticle","title":"First-Order Rewritability of Atomic Queries in Horn Description Logics","authors":[{"name":"Meghyn Bienvenu","slug":"meghyn-bienvenu","given":"Meghyn","family":"Bienvenu","affiliation":""},{"name":"Carsten Lutz","slug":"carsten-lutz","given":"Carsten","family":"Lutz","affiliation":""},{"name":"Frank Wolter","slug":"frank-wolter","given":"Frank","family":"Wolter","affiliation":""}],"abstract":"One of the most advanced approaches to querying data in the presence of ontologies is to make use of relational database systems, rewriting the original query and the ontology into a new query that is formulated in SQL or, equivalently, in first-order logic (FO). For ontologies written in many standard description logics (DLs), however, such FO-rewritings are not guaranteed to exist. We study FO-rewritings and their existence for a basic class of queries and for ontologies formulated in Horn DLs such as Horn-SHI and EL. Our results include characterizations of the existence of FO-rewritings, tight complexity bounds for deciding whether an FO-rewriting exists (ExpTime and PSpace), and tight bounds on the (worst-case) size of FO-rewritings, when presented as a union of conjunctive queries.","doi":null,"url":"https://ijcai.org/proceedings/2013/118","pdf":"https://ijcai.org/proceedings/2013/0118.pdf","markdown":"https://ijcai.org/proceedings/2013/118.md","bibtex":"https://ijcai.org/proceedings/2013/bibtex/118","volume":{"slug":"2013","title":"Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2013","url":"https://ijcai.org/proceedings/2013/","year":2013,"location":"Beijing, China","dates":"3–9 August 2013","editors":"Francesca Rossi","isbn":"978-1-57735-633-2","publisher":"AAAI Press / International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":null,"track":"","number":118,"pages":{"first":754,"last":759},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}