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Re: OWL 2 SS&FSS spec. - overly overloaded grammar/object terminology

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Tue, 15 Sep 2009 23:54:09 +0100
Message-Id: <630DA5F8-1AE4-408C-8BC5-DB7E7927D918@comlab.ox.ac.uk>
Cc: public-owl-comments@w3.org
To: Daniel Barclay <daniel@fgm.com>
Dear Daniel,

Thank you for your comment
      <http://lists.w3.org/Archives/Public/public-owl-comments/ 
2009Sep/0010.html>
on the OWL 2 Web Ontology Language last call drafts.

The structure of OWL ontologies is defined using UML. In the text,  
Functional Syntax is used to refer to the UML structures. The purpose  
of the narrative explanations and examples is to provide informal and  
intuitive explanations. This may sometimes involve relatively  
informal use of the Functional Syntax, but we feel that this  
informality is justified in making the document more approachable.  
Those needing formal definitions can and should refer to the UML and  
to the "Complete Grammar" Appendix [1].

We were aware of the possible confusion between UML classes/instances  
and ontology classes/instances and were careful to ensure that we  
explicitly say "UML Class" or "instance of UML Class" whenever we are  
referring to the former. We now explicitly mention this, as well as  
clarifying some other issues related to the use of UML, in Section  
2.1 [2]. To review these changes please refer to the relevant diff [3].

For example, when we say "An intersection class expression  
ObjectIntersectionOf( CE(1) ... CE(n) ) contains all individuals that  
are instances of all class expressions CE(i) for 1  i  n", we are  
referring to ontology class expressions (that is, instances of the  
UML class ClassExpression), and we are simply providing an informal  
explanation of the semantics of the intersection class expression.

[1] http://www.w3.org/2007/OWL/wiki/ 
Syntax#Appendix:_Complete_Grammar_.28Normative.29

[2] http://www.w3.org/2007/OWL/wiki/Syntax#Structural_Specification

[3] http://www.w3.org/2007/OWL/wiki/index.php? 
title=Syntax&diff=25572&oldid=25485

Please acknowledge receipt of this email to <mailto:public-owl- 
comments@w3.org> (replying to this email should suffice). In your  
acknowledgment please let us know whether or not you are satisfied  
with the working group's response to your comment.

Regards,
Ian Horrocks
on behalf of the W3C OWL Working Group
Received on Tuesday, 15 September 2009 22:54:48 GMT

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