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ACTION-280 completed

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Wed, 4 Feb 2009 20:36:22 +0000
Message-Id: <6D77840D-121C-4BB3-878E-5CE2AD9177CB@cs.man.ac.uk>
To: public-owl-wg Working Group <public-owl-wg@w3.org>

http://www.w3.org/2007/OWL/wiki/LC_Responses/FH4

The message is also appended below as well.

Cheers,
Bijan.

To: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
CC: public-owl-comments@w3.org
Subject: [LC response] To Frank van Harmelen

Dear Frank,

Thank you for your comment
      <http://lists.w3.org/Archives/Public/public-owl-comments/ 
2009Jan/0037.html>
on the OWL 2 Web Ontology Language last call drafts.

First, we'd like to note that this is not a change to the *language*  
but merely a change in the *presentation* of the language. No new  
capability, esp. from the RDF perspective, has occurred. In the old  
specification:

     <http://www.w3.org/TR/owl-semantics/>
the patterns of admissible blank nodes (roughly, tree like patterns  
that can be mapped to nested someValuesOf) could be specified without  
recourse to nodeIDs due to the (tree-like) frame structure of  
Abstract syntax constructions. Unfortunately, this is not possible in  
the new functional syntax, hence we must make use of a different  
mechanism to express the same point. Additionally, we believe there  
is value in having explicit nodeIDs, borrowing from RDF, since it  
makes it clear that there is an actual, significant syntax item there.

Here is an example of the difficulty (following the productions in  
<http://www.w3.org/TR/owl-semantics/syntax.html#2.2>):

"""The syntax here is set up to somewhat mirror RDF/XML syntax [RDF  
Syntax] without the use of rdf:nodeID.""" ABSTRACT SYNTAX:

   Individual(anObjectProperty
                 Individual(aDataProperty "foo"))
TURTLE:

   [anObjectProperty
          [aDataProperty "foo"]]
TURTLE WITH NODEIDS:

    _:x anObjectProperty _:y.
    _:y aDataProperty "foo".
FUNCTIONAL SYNTAX:

   PropertyAssertion(anObjectProperty _:x _:y)
   PropertyAssertion(aDataProperty _:y "Foo")
This is essentially an issue of surface syntax used in the  
specification. The FS is designed such that axioms in the FS  
correspond to axioms in first order logic (which makes various  
specification issues easier). This makes it impossible to use  
implicit BNodes. Furthermore, given the tradition of using nodeIDs,  
we feel we are well within best practice.

Accordingly, the working group has decided not to make the change  
you've suggested.

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,
Bijan Parsia
on behalf of the W3C OWL Working Group
Received on Wednesday, 4 February 2009 20:32:57 GMT

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