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Re: aboutEach: attr val use/mention bug

From: Dan Connolly <connolly@w3.org>
Date: Tue, 05 Jun 2001 11:47:24 -0500
Message-ID: <3B1D0D1C.F3D12FF7@w3.org>
To: Brian McBride <bwm@hplb.hpl.hp.com>
CC: www-rdf-comments@w3.org
Brian McBride wrote:
> 
> 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?

I'm happy for him to say, on the errata page, that
"... value is a collection ..." is an error. But
I'm not sure what to suggest as a correction yet.

[Ralph isn't critical path for that, though, is he?
If the WG decides it's an error, you can do it, no?]

But I'm much more interested in
the WG's disposition of the test case I submitted
than the editorial details. Is it an RDF document?
If so, what's the n-triples equivalent?

The simplest answer that meets my needs is: "no,
it's not an RDF document; there is no rdf:aboutEach
attribute in RDF; we're sorry for creating any
impression that there was one.": ;-)

My answer continues...
"Stay tuned for a rules language specification which
will allow you to say express this sort of thing
and much more. If you agree that there never
was an rdf:aboutEach attribute in RDF, we're
likely to get to a specification of rules sooner.
By the way, here's an XSLT transformation that
will take any XML document with rdf:aboutEach
in it and produce an RDF document that, when
combined with some rules, says
what you probably meant to say:
http://www.w3.org/2001/04rs22/aboutEachSugar.xsl
http://www.w3.org/2001/04rs22/#ae

"


(hmm... I should probably change that aboutEachSugar.xsl
and aboutEachRules.n3 to use a different namespace
for the 1st-class-object version of rdf:aboutEach.)


I include the test case here to reiterate it; note
that it'll work fine with the rules-based interpretation
of aboutEach:

> > 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 12:48:35 GMT

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