- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Mon, 05 Nov 2007 06:13:07 -0500 (EST)
- To: danny.ayers@gmail.com
- Cc: schneid@fzi.de, public-owl-dev@w3.org
From: "Danny Ayers" <danny.ayers@gmail.com> Subject: Re: [OWLWG-COMMENT] Punning and the "properties for classes" use case Date: Mon, 5 Nov 2007 10:48:39 +0100 > Hi Peter, > > I'd be grateful if you could help me with this one point - > > On 02/11/2007, Peter F. Patel-Schneider <pfps@research.bell-labs.com> wrote: > > > Well, RDF overloads URIs already. A URI in RDF denotes a entity in the > > domain of discourse as well as that entity's property extension, which > > also carries the entity's class extension. > > I assumed the resource identification here was (very loosely) like > saying 'that bag of peanuts' - the peanuts inside are an implicit > characteristic of the thing identified, even though you might not be > able to see them. Perhaps you could contrast RDF's approach with > another (OWL 1.1's?) which doesn't overload? > > Cheers, > Danny. Well OWL DL and OWL 1.1 overload as well, at least in some sense. OWL DL with separated vocabularies does not overload this way (pretty much). A URI can denote only one of an individual, a property, or a class. Many treatments of set theory do not overload this way. Elements of the domain of discourse *are* sets, not individuals that have associated sets. This does not prevent the set elements of the domain of discourse from participating in arbitrary relationships, of course. The distinction is to a large extent not particularly interesting, at least as far as I am concerned. What does it matter that in some contexts a URI is an individual and in others it is a class? If one wants a single denotation for a URI one can finess the difference in multiple ways, e.g., the RDF way or considering the single denotation to have several components. peter
Received on Monday, 5 November 2007 11:24:06 UTC