- From: Boris Motik <boris.motik@comlab.ox.ac.uk>
- Date: Thu, 22 Nov 2007 10:58:47 -0000
- To: "'Jeremy Carroll'" <jjc@hpl.hp.com>
- Cc: "'OWL Working Group WG'" <public-owl-wg@w3.org>
Hello, But dc:creator is usually an annotation property, right? I was here referring to object and data properties. Also, you are free to come up with whatever usage restrictions/semantics for OWL 1.1 Full. OWL 1.1 DL, however, must be two-sorted: the interpretation domains of the abstract and the concrete ___domain must be disjoint. This is a hard decidability requirement. Thus, in OWL 1.1 DL, whenever you use a piece of vocabulary, you really need to know whether this usage refers to the abstract or the concrete ___domain. Given this fundamental requirement of OWL 1.1 DL, you have two possibilities. 1. You can type the usage of the vocabulary. In this case, you can write both ObjectSomeValuesFrom( dc:creator A ) and DataSomeValuesFrom( dc:creator A ). Because the usage is typed, you know that in the first case you really meant "the variant of dc:creator which connects two individuals", and in the second case you really meant "the variant of dc:creator which connects an individual with a data value". This is what we did in the proposed OWL 1.1 spec, but people didn't like it and they deem it to be ugly. 2. You can require a strict separation of the vocabulary. In this case, you can write SomeValuesFrom( dc:creator A ); however, in order to know how to interpret dc:creator, you need to have an explicit type for it, which can be *either* owl:ObjectProperty *or* owl:DatatypeProperty. This is what I proposed as a potential solution to the ugliness problem, but alas, people again seem not to like it. Well, I don't see a third possibility (other than lumping the concrete and the abstract interpretation together, which is just not an option for OWL 1.1 DL); however, if someone has an idea how to get out of this conundrum, I'm all ears. Boris > -----Original Message----- > From: Jeremy Carroll [mailto:jjc@hpl.hp.com] > Sent: 22 November 2007 10:42 > To: Boris Motik > Cc: 'OWL Working Group WG' > Subject: Re: ISSUE-65 (excess vocab): REPORTED: excessive duplication of vocabulary > > Boris Motik wrote: > > > I do not expect that users will actually want to use the same URI as both > > an object and a data property. > > My users do. > > e.g. dc:creator is sometimes used with a string, being the name, and > sometimes with a more complex object > > Perhaps my users don't count? > > Jeremy
Received on Thursday, 22 November 2007 10:59:31 UTC