We tackle the problem of defining a well-founded semantics (WFS) for Datalog rules with existentially quantified variables in their heads and negations in their bodies. In partic...
Answering queries over ontologies is an important issue for the Semantic Web. Aggregate queries were widely studied for relational databases but almost no results are known for ag...
Diego Calvanese, Evgeny Kharlamov, Werner Nutt, Ca...
Abstract. Answer set programming (ASP) is a powerful formalism for knowledge representation and common sense reasoning that allows disjunction in rule heads and nonmonotonic negati...
We present a query processing procedure for conjunctive queries in distributed ontology systems where a large ontology is divided into ontology fragments that are later distributed...
The DL-Lite family of Description Logics has been designed with the specific goal of allowing for answering complex queries (in particular, conjunctive queries) over ontologies w...