- From: pat hayes <phayes@ai.uwf.edu>
- Date: Sun, 22 Sep 2002 18:23:40 -0500
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: www-rdf-comments@w3.org
>I was wrong in my initial speculation that making the semantic constraint for >rdfs:subClassOf an iff constraint would not have RDFS-observable >consequences. > >If the semantic constraint for rdfs:subClassOf is changed to an iff >constraint then > > rdf:type rdfs:domain foo . > >would entail > > rdfs:Resource rdfs:subClassOf foo. Ah, most ingenious. OK, but I think this is harmless. It doesn't work for arbitrary domains, and the domain of rdf:type is already required to be the universe. What you have noticed is that trying to restrict that domain to a subset of the universe only makes the universe smaller, in effect. The moral is that one cannot sensibly use RDF to restrict the domain of the rdf:type property. Which is in fact hardly surprising, since to do so would be to change the definition of 'class' and hence of subClassOf. Also it depends on exactly how the condition is worded. I'll think about that some more. Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Sunday, 22 September 2002 19:23:36 UTC