- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Wed, 01 Apr 2009 14:26:40 -0400 (EDT)
- To: public-owl-wg@w3.org
As far as I know, the changes from OWL 1 to OWL 2 are additions, with only a very few exceptions. The differences could be described as follows: OWL 2 is almost entirely compatible with OWL 1, both syntactically and semantically. The functional syntax for OWL 2 is organized differently than the abstract syntax for OWL 1, but every construct in the OWL 1 abstract syntax has a directly corresponding construct in the OWL 2 functional syntax. Just as in OWL 1, OWL 2 can handle all RDF graphs. The vocabulary that is given special meaning in OWL 2 includes the special vocabulary of OWL 1. However, the use of owl:DataRange is deprecated -- rdfs:Datatype should be used instead. The direct semantics for OWL 2 is almost completely compatible with the direct semantics for OWL 1. The only difference is that annotations are semantics-free in the direct semantics for OWL 2. The RDF-based semantics for OWL 2 is completely compatible with the RDF-based semantics for OWL 1. Some of the details of this semantics have changed, but the set of inferences are the same. The treatment of importing in RDF documents has changed slightly in OWL 2 if the RDF graphs are to be considered as OWL 2 DL ontologies. In OWL 1, importing happened first, so the entire merged graph was considered as one unit. In OWL 2, the individual documents are considered separately in most cases. This means that there are some groups of documents that could form an OWL 1 DL ontology but that do not form OWL 2 DL ontologies.
Received on Wednesday, 1 April 2009 18:26:07 UTC