76 citations · 512 across the 33 of their papers we have counts for
9 papers · 1 filter
How to Approximate Ontology-Mediated Queries
Anneke Haga, Carsten Lutz, Leif Sabellek +1
We introduce and study several notions of approximation for ontology-mediated queries based on the description logics ALC and ALCI. Our approximations are of two kinds: we may (1)…
First Order-Rewritability and Containment of Conjunctive Queries in Horn Description Logics
Meghyn Bienvenu, Peter Hansen, Carsten Lutz +1
We study FO-rewritability of conjunctive queries in the presence of ontologies formulated in a description logic between EL and Horn-SHIF, along with related query containment prob…
From Conjunctive Queries to Instance Queries in Ontology-Mediated Querying
Cristina Feier, Carsten Lutz, Frank Wolter
We consider ontology-mediated queries (OMQs) based on expressive description logics of the ALC family and (unions) of conjunctive queries, studying the rewritability into OMQs base…
Separating Positive and Negative Data Examples by Concepts and Formulas: The Case of Restricted Signatures
Jean Christoph Jung, Carsten Lutz, Hadrien Pulcini +1
We study the separation of positive and negative data examples in terms of description logic (DL) concepts and formulas of decidable FO fragments, in the presence of an ontology. I…
Query Inseparability for ALC Ontologies
Elena Botoeva, Carsten Lutz, Vladislav Ryzhikov +2
We investigate the problem whether two ALC ontologies are indistinguishable (or inseparable) by means of queries in a given signature, which is fundamental for ontology engineering…
Inseparability and Conservative Extensions of Description Logic Ontologies: A Survey
Elena Botoeva, Boris Konev, Carsten Lutz +3
The question whether an ontology can safely be replaced by another, possibly simpler, one is fundamental for many ontology engineering and maintenance tasks. It underpins, for exam…