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Re: refining closure text for rdfs-isDefinedBy-semantics

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Date: Fri, 14 Jun 2002 17:10:02 +0100 (BST)
To: patrick hayes <phayes@ai.uwf.edu>
cc: fmanola@mitre.org, w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
Message-ID: <Pine.GSO.4.44.0206141700110.27038-100000@mail.ilrt.bris.ac.uk>

On Fri, 14 Jun 2002, patrick hayes wrote:

> >Pat--
> >
> >How about some suggestions for what we ought to mean by "define"?
> Perhaps I didn't make my rhetorical point clear enough. I don't think
> it has any meaning. What I would like to say about "isDefinedBy" is
> something like "this is completely meaningless, but if it makes you
> feel good, you can use it to point to something."  Which, of course,
> would make one wonder just why we even have "isDefinedBy" in the
> language at all. Yes, exactly.
> I'm willing to be disabused. If someone in the WG thinks it does mean
> something, then by all means explain what that is, preferably with a
> test case involving an entailment. But saying, in essence, "
> 'isDefinedBy' means is defined by" , doesn't actually tell the reader
> (or me) anything.

The discussion after-hours seemed to be less concerned with
model-theoretic semantics (which don't deal with this at all, and
rightly so) but with application-level and process-level use cases:
namely, building RDF "management" applications for dealing with
sets of schema elements (or "vocabularies", I think the term was used).

Danbri says, for a term (property, class, etc) there is someone who
"owns" or produced the definition for it, so he wants this to act as a
pointer to something that gives a handle onto that.

There may also be machine-processable uses where the thing on the sharp
end of iDB is dereferenced to pull back schema element definitions.

These seem to be two loosely-related notions, both of which have
a plausible application-level story.

(A more complex use case to do with schema and subschema
management where different properties of schema elements are managed in
different places was raised in the after-hours talk but I'll leave that
to the person who raised it to elaborate.)

Basically, as you might expect from a loaded term like "defined", people
still seem to have a few notions as to what it means - most of which are
at the application level, not at the level of individual triples or the

jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287088 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk
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Received on Friday, 14 June 2002 12:11:17 UTC

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