- From: Graham Klyne <GK@ninebynine.org>
- Date: Mon, 12 Sep 2005 15:52:40 +0100
- To: Bijan Parsia <bparsia@isr.umd.edu>
- CC: andy.seaborne@hp.com, public-rdf-dawg-comments@w3.org
Bijan Parsia wrote: >>> Section 2.3 >>> Concerning the reference to literals-as-subjects. Is this still an >>> option for the Semantic Web family? I understand that OWL (or >>> OWL-DL) requires that subjects be URIs. Maybe not a problem, but I >>> thought I'd mention it. >> >> >> Not editorial. >> Comments? > > > RDF through OWL syntactically forbids literals-as-subjects. However, > OWL Full allows for equality relations between data values and abstract > individuals. So, semantically, there is already a sense in which the > OWL Family allows for literal subjects. > > Furthermore, there a smooth path to OWL-DL with subjects as > literals...first order logic certainly allows for the first place of > two place predicates to have data values (when it admits such values at > all) and OWL-DL is a proper subset of FOL. It could be that certain > extensions to literal subjects would be undecidable, but so's SWRL for > example. I would expect that a forml of AL-Log would allow for literal > subjects and robust decidability. > > In fact, if you were careful about equalities and class membership, it > might be a reasonable addition to regular OWL-DL. > > Hope this helps. Yes, thanks for clarifying. I thought it might come out as something like this, but it's good to have an OWL expert confirm this. #g -- Graham Klyne For email: http://www.ninebynine.org/#Contact
Received on Tuesday, 13 September 2005 07:43:05 UTC