- From: Bijan Parsia <bparsia@isr.umd.edu>
- Date: Mon, 12 Sep 2005 09:13:55 -0400
- To: andy.seaborne@hp.com
- Cc: public-rdf-dawg-comments@w3.org, Graham Klyne <GK@ninebynine.org>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
On Sep 12, 2005, at 7:15 AM, Seaborne, Andy wrote: > > Editorial changes made in response to > http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Sep/ > 0002 > > Not all the comments are editorial. > > Someone might care to comment on the OWL and literals-as-subjects > comment. See below. > Graham Klyne wrote: [snip] > ... >> 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. Cheers, Bijan Parsia.
Received on Monday, 12 September 2005 13:14:03 UTC