{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T17:26:42Z","timestamp":1790443602909,"version":"4.1.0"},"publisher-location":"California","reference-count":0,"publisher":"International Joint Conferences on Artificial Intelligence Organization","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2017,8]]},"abstract":"<jats:p>We consider ontology-mediated queries (OMQs) based on an EL\n\n  ontology and an atomic query (AQ), provide an ultimately\n\n  fine-grained analysis of data complexity and study rewritability\n\n  into linear Datalog-aiming to capture linear recursion in SQL.\n\n  Our main results are that every such OMQ is in AC0, \n\n  NL-complete or PTime-complete, and that containment in NL\n\n  coincides with rewritability into linear Datalog (whereas\n\n  containment in AC0 coincides with rewritability into first-order\n\n  logic). We establish natural characterizations of the three cases,\n\n  show that deciding linear Datalog rewritability (as well as the\n\n  mentioned complexities) is ExpTime-complete, give a way to\n\n  construct linear Datalog rewritings when they exist, and prove that\n\n  there is no constant bound on the arity of IDB relations in linear\n\n  Datalog rewritings.<\/jats:p>","DOI":"10.24963\/ijcai.2017\/164","type":"proceedings-article","created":{"date-parts":[[2017,7,28]],"date-time":"2017-07-28T05:14:07Z","timestamp":1501218847000},"page":"1181-1187","source":"Crossref","is-referenced-by-count":4,"title":["Ontology-Mediated Querying with the Description Logic EL: Trichotomy and Linear Datalog Rewritability"],"prefix":"10.24963","author":[{"given":"Carsten","family":"Lutz","sequence":"first","affiliation":[{"name":"University of Bremen, Computer Science Department"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leif","family":"Sabellek","sequence":"additional","affiliation":[{"name":"University of Bremen, Computer Science Department"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10584","event":{"name":"Twenty-Sixth International Joint Conference on Artificial Intelligence","theme":"Artificial Intelligence","location":"Melbourne, Australia","acronym":"IJCAI-2017","number":"26","sponsor":["International Joint Conferences on Artificial Intelligence Organization (IJCAI)","University of Technology Sydney (UTS)","Australian Computer Society (ACS)"],"start":{"date-parts":[[2017,8,19]]},"end":{"date-parts":[[2017,8,26]]}},"container-title":["Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence"],"original-title":[],"deposited":{"date-parts":[[2017,7,28]],"date-time":"2017-07-28T07:52:34Z","timestamp":1501228354000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ijcai.org\/proceedings\/2017\/164"}},"subtitle":[],"proceedings-subject":"Artificial Intelligence Research Articles","short-title":[],"issued":{"date-parts":[[2017,8]]},"references-count":0,"URL":"https:\/\/doi.org\/10.24963\/ijcai.2017\/164","relation":{},"subject":[],"published":{"date-parts":[[2017,8]]}}}