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Re: owl.owl

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 12 Mar 2003 00:18:42 -0500
Message-Id: <p05200f25ba947234a19d@[192.168.1.15]>
To: Guus Schreiber <schreiber@swi.psy.uva.nl>, WebOnt WG <www-webont-wg@w3.org>

At 17:13 +0100 3/11/03, Guus Schreiber wrote:
>I have heard some say that they expect people to explicitly import 
>the owl.owl file in any OWL ontology. I'm not sure this is the right 
>strategy. However, if we want poepl to do this there is a problem: 
>owl:Nothing is defined in owl.owl, so OWL Lite ontologies importing 
>owl.owl would automatically become OWL DL ontologies. [Also, the 
>Dublin Core annotations need to be typed with 
>owl:AnnotationProperty, but that can be fixed.]
>
>If we want poepl to import this file, we need to have at least a 
>separate version for OWL Lite. If we go down that road, we might as 
>well make separate versions for all sublanguages, and include 
>some/most/all of the distinctions between the sublanguages. This 
>would, however, require the use of OWL itself in owl.owl, as RDFS is 
>not powerful engouh to express the differences.
>
>Any thoughts?
>
>Guus
>

I believe it would be a serious mistake for people to import the 
owl.owl file and/or for us to set things up in a way that encourages 
this.  The owl.owl file should be used as a required namespace, which 
is standardly used so that your use of the term owl:xxx is consistent 
with other folks -- this is important, because if the file is 
imported and someone says something like

<:class rdf:ID="foo" />

there will be virtually know way for most namespace smart tools (many 
of which already exist) to know that this is a use of owl:class -- 
note the test becomes somewhat complex because if someone imports 
owl.owl and then changes the definition of class, then the above 
would not be an owl:class, but if they wanted to do same using 
namespaces, it doesn't happen because a syntactic check can be used 
to see if the class referred to is "http://www.w3.org/.../owl#class" 
as opposed to anything else.
  -JH


-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
http://www.cs.umd.edu/users/hendler
Received on Wednesday, 12 March 2003 00:36:22 GMT

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