%0 Book Section %B Handbook of the History of Logic %D 2014 %T Description Logics %A Matthias Knorr %A Pascal Hitzler %E Dov. M. Gabbay %E John Woods %E Jörg Siekmann %B Handbook of the History of Logic %I Elsevier %V 9 %P 679-710 %G eng %0 Conference Paper %B Web Reasoning and Rule Systems - 6th International Conference, RR 2012, Vienna, Austria, September 10-12, 2012. Proceedings %D 2012 %T Recent Advances in Integrating OWL and Rules %A Matthias Knorr %A David Carral %A Pascal Hitzler %A Adila Krisnadhi %A Frederick Maier %A Cong Wang %E Markus Krötzsch %E Umberto Straccia %K description logics %K OWL %K Rules %X As part of the quest for a unifying logic for the Semantic Web Technology Stack, a central issue is finding suitable ways of integrating description logics based on the Web Ontology Language (OWL) with rule-based approaches based on logic programming. Such integration is difficult since naive approaches typically result in the violation of one or more desirable design principles. For example, while both OWL 2 DL and RIF Core (a dialect of the Rule Interchange Format RIF) are decidable, their naive union is not, unless carefully chosen syntactic restrictions are applied. We report on recent advances and ongoing work by the authors in integrating OWL and rulesWe take an OWL-centric perspective, which means that we take OWL 2 DL as a starting point and pursue the question of how features of rulebased formalisms can be added without jeopardizing decidability. We also report on incorporating the closed world assumption and on reasoning algorithms. This paper essentially serves as an entry point to the original papers, to which we will refer throughout, where detailed expositions of the results can be found. %B Web Reasoning and Rule Systems - 6th International Conference, RR 2012, Vienna, Austria, September 10-12, 2012. Proceedings %I Springer %C Austria, Vienna %V 7497 %P 225-228 %8 09/2012 %G eng %U http://dx.doi.org/10.1007/978-3-642-33203-6_20 %R 10.1007/978-3-642-33203-6_20 %0 Conference Paper %B ECAI 2012 - 20th European Conference on Artificial Intelligence. Including Prestigious Applications of Artificial Intelligence (PAIS-2012) System Demonstrations Track %D 2012 %T Reconciling OWL and Non-monotonic Rules for the Semantic Web %A Matthias Knorr %A Pascal Hitzler %A Frederick Maier %E Luc De Raedt %E Christian Bessière %E Didier Dubois %E Patrick Doherty %E Paolo Frasconi %E Fredrik Heintz %E Peter J. F. Lucas %X

We propose a description logic extending SROIQ (the description logic underlying OWL 2 DL) and at the same time encompassing some of the most prominent monotonic and nonmonotonic rule languages, in particular Datalog extended with the answer set semantics. Our proposal could be considered a substantial contribution towards fulfilling the quest for a unifying logic for the Semantic Web. As a case in point, two non-monotonic extensions of description logics considered to be of distinct expressiveness until now are covered in our proposal. In contrast to earlier such proposals, our language has the “look and feel” of a description logic and avoids hybrid or first-order syntaxes.

%B ECAI 2012 - 20th European Conference on Artificial Intelligence. Including Prestigious Applications of Artificial Intelligence (PAIS-2012) System Demonstrations Track %I IOS Press %C Montpellier, France %V 242 %P 474–479 %G eng %U http://dx.doi.org/10.3233/978-1-61499-098-7-474 %R 10.3233/978-1-61499-098-7-474 %0 Journal Article %J Artificial Intelligence %D 2011 %T Local Closed World Reasoning with Description Logics under the Well-Founded Semantics %A Matthias Knorr %A José Júlio Alferes %A Pascal Hitzler %K Description Logic %K Knowledge representation %K Logic Programming %K Non-monotonic reasoning %K Ontologies %K Semantic Web %X

An important question for the upcoming Semantic Web is how to best combine open world ontology languages, such as the OWL-based ones, with closed world rule-based languages. One of the most mature proposals for this combination is known as hybrid MKNF knowledge bases [52], and it is based on an adaptation of the Stable Model Semantics to knowledge bases consisting of ontology axioms and rules. In this paper we propose a well-founded semantics for nondisjunctive hybrid MKNF knowledge bases that promises to provide better efficiency of reasoning, and that is compatible with both the OWL-based semantics and the traditional Well-Founded Semantics for logic programs. Moreover, our proposal allows for the detection of inconsistencies, possibly occurring in tightly integrated ontology axioms and rules, with only little additional effort. We also identify tractable fragments of the resulting language.

%B Artificial Intelligence %V 175 %P 1528–1554 %G eng %U http://dx.doi.org/10.1016/j.artint.2011.01.007 %N 9-10 %R 10.1016/j.artint.2011.01.007