Query-Based Entailment and Inseparability for ALC Ontologies (Full Version)

Query-Based Entailment and Inseparability for ALC Ontologies

We investigate the problem whether two ALC knowledge bases are indistinguishable by queries over a given vocabulary. We give model-theoretic criteria and prove that this problem is undecidable for conjunctive queries (CQs) but decidable in 2EXPTIME for unions of rooted CQs. We also consider the problem whether two ALC TBoxes give the same answers to any query in a given vocabulary over all ABox...

When is Query Inseparability for ALC Ontologies Decidable?

An Argumentative Semantics for Paraconsistent Reasoning in Description Logic ALC

It is well known that description logics cannot tolerate the incomplete or inconsistent data. Recently, inconsistency handling in description logics becomes more and more important. In this paper, we present an argumentative semantics for paraconsistent reasoning in inconsistent ontologies. An argumentative framework based on argument trees is provided to model argumentation in description logi...

Deciding inseparability and conservative extensions in the description logic EL

We study the problem of deciding whether two ontologies are inseparable w.r.t. a signature Σ, i.e., whether they have the same consequences in the signature Σ. A special case is to decide whether an extension of an ontology is conservative. By varying the language in which ontologies are formulated and the query language that is used to describe consequences, we obtain differ-ent versions o...

Conjunctive Query Inseparability of OWL 2 QL TBoxes

The OWL2 profile OWL2QL, based on the DL-Lite family of description logics, is emerging as a major language for developing new ontologies and approximating the existing ones. Its main application is ontology-based data access, where ontologies are used to provide background knowledge for answering queries over data. We investigate the corresponding notion of query inseparability (or equivalence...