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RE: Comments on the new RDF Test Cases draft

From: Massimo Marchiori <massimo@w3.org>
Date: Fri, 31 May 2002 19:58:25 +0200
To: "Jan Grant" <Jan.Grant@bristol.ac.uk>
Cc: "www-rdf-comments" <www-rdf-comments@w3.org>
Message-ID: <NGBBJNKIMLOPPCFHEJEMIEAFCPAA.massimo@w3.org>



> -----Original Message-----
> From: Jan Grant [mailto:Jan.Grant@bristol.ac.uk]
> Sent: Friday, May 31, 2002 11:35 AM
> To: Brian McBride
> Cc: Massimo Marchiori; phayes; www-rdf-comments
> Subject: RE: Comments on the new RDF Test Cases draft
>
>
> On Fri, 31 May 2002, Jan Grant wrote:
>
> [I've lost the attributions, sorry]
>
> > > >Therefore, such "word smoothering", plus a precise definition of
> > > >isomorphism, suffice. But, note that if we go along the
> > > >"smoothering way", the same problem of a precise definition of
> > > >isomorphism can be nicely dropped as well, as the wording can well
> > > >say that the "expected output" is the given N-triple one, and just
> > > >be silent on the isomorphism issues at all (as, it's rather clear
> > > >that N-triple output is defined modulo renaming of blank nodes, and
> > > >in any case, crucially, no *formal* definition is then needed as
> > > >the Test Cases contain clarification guidelines, and not formal
> > > >normative definition of "test passing for parsers").
>
> Ack! I didn't notice this before!
>
> I should say that jeremy Carroll is producing a document describing what
> we mean by "an RDF graph" including an expression of the appropriate
> notion of isomorphism.
>
> But I see you're talking about "renaming blank nodes". Blank nodes
> _don't_ have names.
> They have identity wrt the graph they're a part of;
> the "names" are simply an artifact of the serialisation syntax and have
> no non-local meaning.
>
> An N-Triples document is just a description of an RDF graph, which may
> contain some blank nodes; they really are (honest!) blank.

This is divergence to the thread, but I was pinged...
<ping>
I was talking about N-triple output, where you do need renaming.
The fact itself blank nodes are "blank" is so well-known like saying pigs
don't fly....
So well-known, that in fact nobody had noticed the current definition
of RDF graph indeed does need renaming (or, "remapping", as you like),
cf http://lists.w3.org/Archives/Public/www-rdf-comments/2002AprJun/0107.html
(optionally, for typo-spotters, integrated with
http://lists.w3.org/Archives/Member/w3c-archive/2002May/0075.html )
So much for pigs flying... ;)
</ping>

-M
Received on Friday, 31 May 2002 13:59:44 GMT

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