{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:53:15Z","timestamp":1753894395673,"version":"3.41.2"},"reference-count":0,"publisher":"Centre pour la Communication Scientifique Directe (CCSD)","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>We study the complexity of answer counting for ontology-mediated queries and\nfor querying under constraints, considering conjunctive queries and unions\nthereof (UCQs) as the query language and guarded TGDs as the ontology and\nconstraint language, respectively. Our main result is a classification\naccording to whether answer counting is fixed-parameter tractable (FPT),\nW[1]-equivalent, #W[1]-equivalent, #W[2]-hard, or #A[2]-equivalent, lifting a\nrecent classification for UCQs without ontologies and constraints due to Dell\net al. The classification pertains to various structural measures, namely\ntreewidth, contract treewidth, starsize, and linked matching number.\n  Our results rest on the assumption that the arity of relation symbols is\nbounded by a constant and, in the case of ontology-mediated querying, that all\nsymbols from the ontology and query can occur in the data (so-called full data\nschema).\n  We also study the meta-problems for the mentioned structural measures, that\nis, to decide whether a given ontology-mediated query or constraint-query\nspecification is equivalent to one for which the structural measure is bounded.<\/jats:p>","DOI":"10.46298\/lmcs-19(3:16)2023","type":"journal-article","created":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T14:24:28Z","timestamp":1694701468000},"source":"Crossref","is-referenced-by-count":0,"title":["Answer Counting under Guarded TGDs"],"prefix":"10.46298","volume":"Volume 19, Issue 3","author":[{"given":"Cristina","family":"Feier","sequence":"first","affiliation":[]},{"given":"Carsten","family":"Lutz","sequence":"additional","affiliation":[]},{"given":"Marcin","family":"Przyby\u0142ko","sequence":"additional","affiliation":[]}],"member":"25203","published-online":{"date-parts":[[2023,9,14]]},"container-title":["Logical Methods in Computer Science"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/lmcs.episciences.org\/12272\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/lmcs.episciences.org\/12272\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T14:24:28Z","timestamp":1694701468000},"score":1,"resource":{"primary":{"URL":"http:\/\/lmcs.episciences.org\/8768"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,14]]},"references-count":0,"URL":"https:\/\/doi.org\/10.46298\/lmcs-19(3:16)2023","relation":{"has-preprint":[{"id-type":"arxiv","id":"2101.03058v3","asserted-by":"subject"},{"id-type":"arxiv","id":"2101.03058v2","asserted-by":"subject"}],"is-same-as":[{"id-type":"arxiv","id":"2101.03058","asserted-by":"subject"},{"id-type":"doi","id":"10.48550\/arXiv.2101.03058","asserted-by":"subject"}]},"ISSN":["1860-5974"],"issn-type":[{"type":"electronic","value":"1860-5974"}],"subject":[],"published":{"date-parts":[[2023,9,14]]},"article-number":"8768"}}