Closed-World Semantics for Conjunctive Queries with Negation over ELH_bottom Ontologies
Aus International Center for Computational Logic
Closed-World Semantics for Conjunctive Queries with Negation over ELH_bottom Ontologies
Vortrag von Walter Forkel
- Veranstaltungsort: APB 3027
- Beginn: 18. April 2019 um 13:00
- Ende: 18. April 2019 um 14:30
- Forschungsgruppe: Automatentheorie
- Event series: KBS Seminar
- iCal
Abstract: Ontology-mediated query answering is a popular paradigm for enriching answers to user queries with background knowledge. For querying the absence of information, however, there exist only few ontology based approaches. Moreover, these proposals conflate the closed-domain and closed-world assumption, and therefore are not suited to deal with the anonymous objects that are common in ontological reasoning. We propose a new closed-world semantics for answering conjunctive queries with negation over ontologies formulated in the description logic ELH-bottom, which is based on the minimal canonical model. We propose a rewriting strategy for dealing with negated query atoms, which shows that query answering is possible in polynomial time in data complexity.
