Re: OWL CR feedback: owl:Class 'vs' rdfs:Class causing pain. Is owl:Class really needed?

>Pat, this is perhaps a useful perspective on
>the matter, but what's at issue in this
>public-webont-comments forum is whether the
>question is answered by the OWL specs.

Well, OK. It is, but you have to kind of dig around to find it.

>
>Please try to answer the question from
>the text of the specs. If you guys just
>want to discuss this stuff free-form, please
>use www-rdf-logic or whatever.

Ok, the specs documents cover this issue at various places, eg see

http://www.w3.org/TR/2003/CR-owl-features-20030818/#s1.3
http://www.w3.org/TR/2003/CR-owl-features-20030818/#s4
http://www.w3.org/TR/2003/CR-owl-ref-20030818/#app-DLinRDF
http://www.w3.org/TR/2003/WD-owl-semantics-20030331/rdfs.html#5.1

See also the comments at
http://www.w3.org/TR/2003/WD-owl-semantics-20030331/rdfs.html#5.4
which gives a more formal description of the OWL-DL restrictions on 
the RDFS universe.

Pat


>On Wed, 2003-09-17 at 21:35, pat hayes wrote:
>>  [...]
>>  >Are all RDF classes OWL classes?
>>
>>  No. RDFS has a more general notion of class than OWL has. In
>>  particular, rdfs:Class is not an OWL class.
>>
>>  >and vice-versa?
>>
>>  Yes.
>>
>>  >Can this be expressed
>>  >with (rdfs):subClassOf?
>>
>>  Yes, in RDFS:
>>
>>  owl:Class rdfs:subClassOf rdfs:Class.
>>
>>  However, this fact is 'invisible' in OWL because of the restrictions
>>  which have been placed on the expressivity of OWL syntax
>
>[...]
>
>
>--
>Dan Connolly, W3C http://www.w3.org/People/Connolly/


-- 
---------------------------------------------------------------------
IHMC	(850)434 8903 or (650)494 3973   home
40 South Alcaniz St.	(850)202 4416   office
Pensacola			(850)202 4440   fax
FL 32501			(850)291 0667    cell
phayes@ihmc.us       http://www.ihmc.us/users/phayes

Received on Thursday, 18 September 2003 19:34:17 UTC