- From: Dan Brickley <danbri@w3.org>
- Date: Fri, 9 May 2003 09:14:42 -0400
- To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Cc: Jan Grant <Jan.Grant@bristol.ac.uk>, Brian McBride <bwm@hplb.hpl.hp.com>, graham Klyne <gk@ninebynine.org>, RDF Core <w3c-rdfcore-wg@w3.org>
* Jeremy Carroll <jjc@hplb.hpl.hp.com> [2003-05-09 14:18+0200] > > > > -----Original Message----- > > If the restriction is that individuals can't be the _object_ of multiple > > triples, we could use an inverse of the 'depicts' of 'member' > > property instead, > > but that's an ugly hack. Is this restriction across all of OWL, > > or just the > > DL & Lite dialects? > > Only OWL DL and OWL Lite. Phew > > > A workaround is as follows. > > <rdf:RDF xml:base="&my;" > xmlns:my="&my;" > > <owl:InverseFunctionalProperty rdf:about="#nodeID" /> > <Image> > <depicts> > <Person> > <my:nodeID rdf:resource="gensym001"/> > <mbox rdf:resource="mailto:danbri@w3.org"/> > </Person> > </Image> > > <Group> > <member> > <Person> > <my:nodeID rdf:resource="gensym001"/> > <homepage rdf:resource="http://www.w3.org/People/DanBri/"/> > </Person> > </member> > </Group> That's a workaround that works at the OWL layers, but takes away the ability for RDF/S tools to be able to answer questions like "what groups is this person in, and what's his/her homepage?". By making things more acceptable to OWL tools, we make them less scrutable to RDF. A painful tradeoff. For FOAF, it's bearable as we use owl:InverseFunctionalProperty a lot anyway. But this isn't (yet...) common practice. Many RDF parsers are acquiring rdf:nodeID support; not so many tools do merging on InverseFunctionals yet. > This forces the two Persons to refer to the same resource, even though they > have different bnodes. You do need to pollute the URI space with the > gensym's, as far as I can tell. (You cannot use strings with > InverseFunctionalProperty's in OWL DL and OWL Lite). Oh, I think I knew that and was trying to forget it. Yet more evidence that the DL/Lite profile of OWL will turn out to be of niche interest, imho. So long as it's allowed in OWL Full I can contain my dissapointment... Dan
Received on Friday, 9 May 2003 09:14:58 UTC