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Re: need to determine what RDF is

From: Dan Brickley <danbri@w3.org>
Date: Thu, 30 May 2002 18:14:54 -0400 (EDT)
To: Dan Connolly <connolly@w3.org>
cc: patrick hayes <phayes@ai.uwf.edu>, <bwm@hplb.hpl.hp.com>, <www-rdf-comments@w3.org>, <em@w3.org>, <w3c-semweb-cg@w3.org>, <pfps@research.bell-labs.com>
Message-ID: <Pine.LNX.4.30.0205301808460.1897-100000@tux.w3.org>

On 30 May 2002, Dan Connolly wrote:

> On Thu, 2002-05-30 at 11:10, patrick hayes wrote:
> > >On Thu, 2002-05-30 at 10:26, Peter F. Patel-Schneider wrote:
> > >[...]
> > >>  I'm only interested in relationships between RDF graphs.  Which such
> > >>  relationships are RDF relationships?
> > >>
> > >>  My view is that the only such relationships are RDF entailment and RDFS
> > >>  entailment.  Any agent that computes any other relationship between RDF
> > >>  graphs is not doing RDF.
> > >
> > >Why is RDFS special? It's just the first of many RDF vocabularies,
> > >no?
> >
> > Its more than just an RDF vocabulary because it has some extra
> > semantic conditions.
> That doesn't look special, to me; I expect each vocabulary
> to come with some extra semantic conditions.

Quite. For eg., there are semantic conditions associated with the Web
resource named http://xmlns.com/foaf/0.1/mbox which are partially but not
completely captured by the observation that it is an unambiguous property.

Re 'not completely':
Web onto languages don't currently give me a way of expressing that it is
what we might call a _static_ unambiguous property; assigning different
values to it on different days is in contravention of that rdf property's
meaning. Well it would be if I'd finished writing that up in prose as part
of the rdf/xml or HTML doc at the namespace. Even though WebOnt doesn't
let me write this machine-readibly, it is still a semantic condition
associated with the property.

This would be a more persuasive argument were I to round out the
definition of 'static unambiguous property'; difficult to do crisply, I
admit, and certainly hard to account for in terms of the RDF MT.


Received on Thursday, 30 May 2002 18:16:56 UTC

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