Finite Entailment of UCRPQs over ALC Ontologies
This work addresses a theoretical problem in description logic and query entailment, providing complexity results for an expressive query language, but it is incremental as it builds on existing classes like UCRPQs and ALC.
The paper tackles the problem of finite entailment of ontology-mediated queries using unions of conjunctive regular path queries (UCRPQs) over ALC ontologies, and shows a tight 2EXPTIME upper bound for this entailment.
We investigate the problem of finite entailment of ontology-mediated queries. We consider the expressive query language, unions of conjunctive regular path queries (UCRPQs), extending the well-known class of union of conjunctive queries, with regular expressions over roles. We look at ontologies formulated using the description logic ALC, and show a tight 2EXPTIME upper bound for entailment of UCRPQs. At the core of our decision procedure, there is a novel automata-based technique introducing a stratification of interpretations induced by the deterministic finite automaton underlying the input UCRPQ