4 papers
First-Order Rewritability of Frontier-Guarded Ontology-Mediated Queries
Pablo Barcelo, Gerald Berger, Carsten Lutz +1
We focus on ontology-mediated queries (OMQs) based on (frontier-)guarded existential rules and (unions of) conjunctive queries, and we investigate the problem of FO-rewritability,…
The Space-Efficient Core of Vadalog
Gerald Berger, Georg Gottlob, Andreas Pieris +1
Vadalog is a system for performing complex reasoning tasks such as those required in advanced knowledge graphs. The logical core of the underlying Vadalog language is the warded fr…
Containment for Rule-Based Ontology-Mediated Queries
Pablo Barcelo, Gerald Berger, Andreas Pieris
Many efforts have been dedicated to identifying restrictions on ontologies expressed as tuple-generating dependencies (tgds), a.k.a. existential rules, that lead to the decidabilit…
A Many-Sorted Variant of Japaridze's Polymodal Provability Logic
Gerald Berger, Lev D. Beklemishev, Hans Tompits
We consider a many-sorted variant of Japaridze's polymodal provability logic . In this variant, which is denoted , propositional variables are assi…