From: Jonathan Rees <email@example.com> Date: Sat, 31 Jan 2009 19:27:17 -0500 Message-Id: <C7BAF8F7-AC6C-495D-BF96-2A7AC3B3BEFA@creativecommons.org> To: firstname.lastname@example.org
The OWL 2 DL imports closure is subject to the prohibition on owl:incompatibleWith imports, while the OWL 2 Full imports closure is not.
It is unfortunate that there are two different definitions of imports closure. Ideally they should be instances of a common pattern, or one should be derived from the other. At least there should be some kind of theorem relating them, such as map-to-SS(import-closure(map-to- graph(O))) ~= import-closure(O) for all (DL) ontologies O, and the former is OK iff the latter is.
To answer the question in the editor's note in section 3 of the RDF- based semantics document: The answer is yes, this document does have to explain what imports mean, somehow, because imports is part of the OWL 2 vocabulary. Maybe your worry is that imports make a lie of the simple statement that every RDF graph has an OWL 2 Full semantics - i.e. graphs (or graph sets) that are not imports closed are not given a meaning. I don't know how to address this correctly but you're going to have to come to terms with this somehow - either retract the claim that all graphs have a meaning, say that the meaning is not RDF- semantics-like (because it relies on chasing imports), or say that unclosed graphs/ graph sets *do* have some meaning.
PeterPatel-Schneider 14:36, 13 February 2009 (UTC)
Thank you for your message
on the OWL 2 Web Ontology Language last call drafts.
The RDF Semantics document was not at last call. It has recently been changed so that imports is no longer a semantic issue. The editor of the RDF Semantics document will be working with you to improve the related presentation issues.
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Regards, Peter F. Patel-Schneider on behalf of the W3C OWL Working Group