- From: Pat Hayes <phayes@ihmc.us>
- Date: Thu, 24 Mar 2011 13:54:33 -0500
- To: Pat Hayes <phayes@ihmc.us>
- Cc: Sandro Hawke <sandro@w3.org>, Michael Schneider <schneid@fzi.de>, Graham Klyne <GK-lists@ninebynine.org>, Dieter Fensel <dieter.fensel@sti2.at>, Enrico Franconi <franconi@inf.unibz.it>, Hugh Glaser <hg@ecs.soton.ac.uk>, Mark Wallace <mwallace@modusoperandi.com>, Alan Ruttenberg <alanruttenberg@gmail.com>, Reto Bachmann-Gmuer <reto.bachmann@trialox.org>, Ivan Shmakov <oneingray@gmail.com>, Ivan Shmakov <ivan@main.uusia.org>, "<semantic-web@w3.org>" <semantic-web@w3.org>
Another quick thought... On Mar 24, 2011, at 12:14 PM, Pat Hayes wrote: > .... >> >>> The one possible exception I can see is the use of bnodes to encode OWL syntax, using the RDF list construction. Clearly, one does not want to have OWL/RDF entailments ruined because a list has been given a name. This might require some special conventions; but in practice, again, this use of RDF has never been seriously intended to be used by RDF inference engines. Rather, this 'encoding' of OWL uses RDF as a serialization mechanism to move OWL around the Web via RDF portals. If we were to make this explicit, we could isolate this from RDF entailment regimes altogether. Which now that I think about it, might be a very good idea. >> >> Is there something in the OWL specs that says OWL doesn't work (or that >> we're no longer in DL) if the nodes composing the lists are not blank? > > Not actually a statement, but the entailments would not work in the same way. (To see why, consider some OWL/RDF and skolemize it two different ways. These two are identical OWL but do not entail one another in RDF.) Yes, this would be a problem. The OWL/RDF spec would have to be re-written. ... Maybe not. Consider a version of RDF in which bnodes are allowed but ONLY in triples encoding RDF collections. They have no semantics, but are treated simply a a syntactic device to string lists together: they are just part (along with the RDF collections vocabulary) of a kind of RDF-specific syntax trick to encode S-expressions in RDF triple syntax. This leaves the OWL specs entirely alone, and still removes blank nodes from the 'real' RDF data, where they are skolemized. Inelegant, but it solves all the practical problems. Pat
Received on Thursday, 24 March 2011 18:55:11 UTC