{"type":"ScholarlyArticle","title":"Combining Existential Rules and Description Logics","authors":[{"name":"Antoine Amarilli","slug":"antoine-amarilli","given":"Antoine","family":"Amarilli","affiliation":""},{"name":"Michael Benedikt","slug":"michael-benedikt","given":"Michael","family":"Benedikt","affiliation":""}],"abstract":"Query answering under existential rules — implications with existential quantifiers in the head — is known to be decidable when imposing restrictions on the rule bodies such as frontier-guardedness [Baget et al., 2010; Baget et al., 2011a]. Query answering is also decidable for description logics [Baader, 2003], which further allow disjunction and functionality constraints (assert that certain relations are functions); however, they are focused on ER-type schemas, where relations have arity two. This work investigates how to get the best of both worlds: having decidable existential rules on arbitrary arity relations, while allowing rich description logics, including functionality constraints, on arity-two relations. We first show negative results on combining such decidable languages. Second, we introduce an expressive set of existential rules (frontier-one rules with a certain restriction) which can be combined with powerful constraints on arity-two relations (e.g. GC2, ALCQIb) while retaining decidable query answering. Further, we provide conditions to add functionality constraints on the higher-arity relations.","doi":null,"url":"https://ijcai.org/proceedings/2015/381","pdf":"https://ijcai.org/proceedings/2015/0381.pdf","markdown":"https://ijcai.org/proceedings/2015/381.md","bibtex":"https://ijcai.org/proceedings/2015/bibtex/381","volume":{"slug":"2015","title":"Proceedings of the Twenty-Fourth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2015","url":"https://ijcai.org/proceedings/2015/","year":2015,"location":"Buenos Aires, Argentina","dates":"25–31 July 2015","editors":"Qiang Yang and Michael Wooldridge","isbn":"978-1-57735-738-4","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Special Track on Knowledge Representation and Reasoning","track":"Special Track on Knowledge Representation and Reasoning","number":381,"pages":{"first":2691,"last":2696},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}