Abstract Information systems have to deal with an increasing amount of data that is
heterogeneous, unstructured, or incomplete. In order to align and complete data, systems …

Enhancing Datalog with existential quantification gives rise to Datalog∃, a powerful
knowledge representation language widely used in ontology-based query answering. In this …

Active integrity constraints (AICs) are a useful formalism to express integrity constraints and
policies to restore consistency in databases violating them. However, AICs do not allow …

This paper studies a stable model semantics for Description Logic (DL) knowledge bases
(KBs) and for (possibly cyclic) terminologies, ultimately showing that terminologies under the …

Extending programming languages with stochastic behaviour such as probabilistic choices
or random sampling has a long tradition in computer science. A recent development in this …

To reason with existential rules (aka tuple-generating dependencies), one often computes
universal models. Among the many such models of different structure and cardinality, the …

Ontology-based query answering with existential rules is well understood and implemented
for positive queries, in particular conjunctive queries. For queries with negation, however …

One of the factors that is hindering the adoption of nonmonotonic description logics in
applications is performance. Even when monotonic and nonmonotonic inferences have the …

This paper partially bridges a gap in the literature on Circumscription in Description Logics
by investigating the tractability of conjunctive query answering in OWL2's profiles. It turns out …

This article deals with the combination of ontologies and rules by means of existential rules
and answer set programming. Existential rules have been proposed for representing …