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Re: aboutEach: attr val use/mention bug

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Wed, 06 Jun 2001 17:27:58 +0100
Message-ID: <3B1E5A0E.AB8CDA10@hplb.hpl.hp.com>
To: Dan Connolly <connolly@w3.org>
CC: www-rdf-comments@w3.org
Dan,

Nice one on the sub-property problem.

I've created a new issue:

  http://www.w3.org/2000/03/rdf-tracking/#rdfms-abouteach

Regarding the use/mention bug.  I'm inclinded to ask Ralph to update the
errata.  Would you agree?

Brian


Dan Connolly wrote:
> 
> Regarding:
> 
>   The value of an aboutEach attribute must be a
>   container.
> 
>   -- http://www.w3.org/TR/REC-rdf-syntax/#containers
> 
> That seems to be a use/mention bug:
> The value of an aboutEach attribute is a URI reference;
> one that *denotes* a collection, no?
> 
> The spec continues:
> 
>   Using a distributive referent on a container is the same
>   as making all the statements about each of the members
>   separately.
> 
> but that doesn't clearly specify how to determine the
> members of a container.
> 
> For example, consider using a subproperty of rdf:_2
> to specify the second member of a collection:
> 
> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>   xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>   xmlns:ex="http://example/vocab#">
>   <r:Description r:about="#books"
>   xmlns:r="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
>     <r:type
>     r:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag" />
> 
>     <r:_1 r:resource="#book1" />
> 
>     <ex:member2 r:resource="#book2" />
> 
>     <r:_3 r:resource="#book3" />
>   </r:Description>
> 
>   <rdf:Description rdf:aboutEach="#books">
>     <dc:rights xmlns:dc="http://purl.org/dc/elements/1.1/">all
>     mine!</dc:rights>
>   </rdf:Description>
> 
>   <rdf:Description rdf:about="http://example/vocab#member2">
>     <rdfs:subPropertyOf
> rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#_2"/>
>   </rdf:Description>
> </rdf:RDF>
> 
> What are the members of #books? is #book2 one of them?
> I can deduce, from the specification of rdfs:subProperty,
> that it is. But knowledge of rdfs:subProperty is not
> required for parsing rdf:aboutEach syntax, is it?
> 
> I tried it with SiRPAC and got:
> 
> ///////
> Errors during parsing
> 
> Fatal error: Unresolved internal reference to books
>    (Line number = 25, Column number = 4)
> \\\\\\\
> 
> --
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 5 June 2001 12:28:57 GMT

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