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Re: proposed response to LC comment 43 sections 2,5,6

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Sat, 14 Feb 2009 23:17:17 +0000
Message-Id: <DBB5B244-222D-42EE-8460-AFF3E4655AE0@comlab.ox.ac.uk>
Cc: public-owl-wg@w3.org
To: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Looks good to me -- thanks!

Ian


On 10 Feb 2009, at 19:11, Peter F. Patel-Schneider wrote:

>
> I am proposing the following response to LC Comment 43 sections 2, 5,
> and 6.
>
> In the absence of disagreement I suggest that the RDF mapping document
> be modified as suggested in the response, the modifications be  
> accepted
> as editorial, and the response sent out.
>
> peter
>
>
>
> Dear Zhe,
>
> Thank you for your message
>   http://lists.w3.org/Archives/Public/public-owl-wg/2009Jan/0083.html
> on the OWL 2 Web Ontology Language last call drafts.
>
> Your message contains multiple sections, affecting more than one
> document, and will thus generate multiple replies.  This response
> is for sections 2, 5, and 6, which affect the mapping from the
> functional syntax to RDF graphs.
>
>
> ************************
> 5. In the RDF mapping document, is it possible to keep OWL 2  
> vocabulary
>    a bit smaller by replacing owl:minQualifiedCardinality with the
>    existing owl:minCardinality?  Same idea applies to
>    owl:qualifiedCardinality, owl:maxQualifiedCardinality.  After all,
>    owl:onClass is there to differentiate the qualified vs.
>    non-qualified case.
> ************************
>
> The problem here has to do with monotonicity of the RDF semantics.
> Consider a qualified min cardinality translation, i.e., something like
> MinCardinality(2 ex:p ex:C), which translates into
>
> 	_:x rdf:type owl:Restriction
> 	_:x owl:minQualifiedCardinality "2"^^xsd:nonNegativeInteger
> 	_:x owl:onProperty ex:p
> 	_:x owl:onClass ex:C
>
> If this suggestion was made the translation would instead be
>
> 	_:x rdf:type owl:Restriction
> 	_:x owl:minCardinality "2"^^xsd:nonNegativeInteger
> 	_:x owl:onProperty ex:p
> 	_:x owl:onClass ex:C
>
> However, this contains the three-triple translation of  
> MinCardinality(2
> ex:p), and The RDF semantic will pick this up, and augment the meaning
> of the above four triples with the meaning for MinCardinality(2 ex:p).
>
> For minimum cardinality things are not so bad, because  
> MinCardinality(2
> ex:p ex:C) implies MinCardinality(2 ex:p).  However for Cardinality  
> and
> MaxCardinality this is not the case, and an incorrect meaning will be
> determined.
>
> This kind of problem has been known ever since the original Web  
> Ontology
> Working Group.  The RDF mapping document does not contain all the
> rationale for the various choices in the mapping, so no change is
> envisioned in response to this part of your comment.
>
>
> ************************
> 2. very minor typo
>     RDF mapping document has a typo in Section 2.2. s/auhtor/author/.
>
> 6. In Section 2.2 of RDF mapping document, are we missing a  
> translation?
>    It is unclear how the second example in 2.2 is translated into
>    triples.  The AnnotationAssertion in Table 1 has three  
> parameters and
>    that example has only two parameters for AnnotationAssertion.
> ************************
>
> The second example in Section 2.2 is
>
> 	AnnotationAssertion( a:Peter
> 	    Annotation(
> 	       Annotation( a:author a:Seth_MacFarlane )
> 	       rdfs:label "Peter Griffin"
> 	    )
> 	)
>
> This is not syntactically correct.  The example was not correctly
> changed from a previous syntax for annotation assertions.  The correct
> example is
>
> 	AnnotationAssertion(
> 	       Annotation( a:author a:Seth_MacFarlane )
> 	       rdfs:label a:Peter "Peter Griffin"
> 	)
>
> namely a singly-annotated annotation assertion.
>
> Thank you for pointing out this error.  You also point out the
> mis-typing of a:author in the example.
>
> The document has been changed to fix these editorial mistakes.  The  
> diffs
> can be found at ..................................
>
>
> 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,
> Peter F. Patel-Schneider
> on behalf of the W3C OWL Working Group
>
Received on Saturday, 14 February 2009 23:17:58 GMT

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