A Story of Logic and OWL
- Speaker: Roman Kontchakov, Department of Computer Science and Information Systems, Birkbeck, University of London
- Date: Wednesday, 16 March 2011 from 16:45 to 17:45
- Location: Room 745, Malet Street.
(There will be cookies and coffee from 16:35, so it is recommended to arrive a bit earlier).
In this talk we look at the classical automated reasoning problem---given a theory with a set of ground atoms and a formula, decide whether the formula follows from the theory. We argue that this problem resurfaces as the main reasoning problem in WWW. We consider, in particular, ontology-based data access (OBDA) and ontology maintenance. In a typical OBDA scenario, the theory is an `ontology' providing a user-oriented view of raw data (ground atoms), and the formula is a query. The latest W3C recommendation for the Web Ontology Language identifies a specialised profile, OWL 2 QL, tailored for ODBA. In this talk we analyse advantages and limitations of the two OBDA paradigms, the query rewriting and the combined approaches, and the ontology languages they can work with (OWL 2 QL and OWL 2 EL). We also demonstrate how the classical notion of conservative extensions can be adapted (we say ontologies are inseparable if the same formulas follow from them) and used in formalising ontology versioning, re-use and module extraction.