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owl:subClassOf ? [was: Re: working on it]

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: 26 Jun 2003 17:48:37 +0100
To: pat hayes <phayes@ihmc.us>
Cc: rdf core <w3c-rdfcore-wg@w3.org>
Message-Id: <1056646117.2782.21.camel@dhcp-91-136.hpl.hp.com>

On Thu, 2003-06-26 at 06:28, pat hayes wrote:
> Guys, I now have connectivity.

:)

> 
> I have been working on a version of the semantics doc along the lines 
> several of us discussed after last Friday's telecon. It is still 
> incomplete, but I will keep a version here:
> 
> http://www.ihmc.us/users/phayes/RDF_Semant_Edit_Weak.html
> 
> I hope it will be reasonably final by Friday, though I may not have 
> the proofs written out until early next week. At the time of sending 
> this email, only section 4 has been rewritten and that not fully; the 
> rule section hasnt been done yet.
> 
> In this, *all* the RDF/S semantic conditions are 'if' not 'iff', so 
> the correspondence to the rules will be easy to establish, and the 
> relevant closure lemmas easy to prove. The only extra condition added 
> is that all classes are subclasses of rdfs:Resource, which I think is 
> needed to make sense of the 'empty' domain and range conditions, and 
> in any case is handled fully by rdfs 7a
> 
> The complete RDFS rules are now rdfs 1, 2, 3,4a,4b,6, 7a, 9,10,11; 
> the correspondence to the semantic conditions is very clear.
> 
> I plan to discuss the 'extensional' versions and mention the extra 
> rules they sanction (5,7b,8,12) but without any claim of 
> completeness. Thus, the overall content will be similar to the last 
> version except that a simple basic RDFS rule set can be complete and 
> included in the normative spec in the way that will make DanC's heart 
> lighter.

I'd like to be sure we understand the relationship of rdfs:subClassOf to
Owl.  As I understand things, the intent is that Owl would retain
extensional semantics.  Is that correct.

If so, then Owl want a stronger notion of subClassOf than that proposed
in this document for rdfs:subClassOf. 

Would that meant that the 'correct' thing for WEBONT to do would be to
define owl:subClassOf as a subproperty of rdfs:subClassOf?

Brian
Received on Thursday, 26 June 2003 12:49:27 EDT

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