3 results
Carsten Lutz ; Inanc Seylan ; Frank Wolter.
In the context of ontology-mediated querying with description logics (DLs), we study the data complexity of queries in which selected predicates can be closed (OMQCs). We provide a non-uniform analysis, aiming at a classification of the complexity into tractable and non-tractable for ontologies in […]
Published on August 28, 2019
Cristina Feier ; Antti Kuusisto ; Carsten Lutz.
We study rewritability of monadic disjunctive Datalog programs, (the complements of) MMSNP sentences, and ontology-mediated queries (OMQs) based on expressive description logics of the ALC family and on conjunctive queries. We show that rewritability into FO and into monadic Datalog (MDLog) are […]
Published on May 23, 2019
Cristina Feier ; Carsten Lutz ; Marcin Przybyłko.
We study the complexity of answer counting for ontology-mediated queries and for querying under constraints, considering conjunctive queries and unions thereof (UCQs) as the query language and guarded TGDs as the ontology and constraint language, respectively. Our main result is a classification […]
Published on September 14, 2023