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Re: SEM: semantics for current proposal (why R disjoint V?) (sameState TEST)

From: Dan Connolly <connolly@w3.org>
Date: 23 Apr 2002 18:14:17 -0500
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: Pat Hayes <phayes@ai.uwf.edu>, www-webont-wg@w3.org
Message-Id: <1019603658.5164.2859.camel@dirk>
On Tue, 2002-04-23 at 17:23, Ian Horrocks wrote:
> On April 8, Pat Hayes writes:
[...]
> > so these issues seem largely irrelevant; whereas the inconvenience 
> > and artificiality of maintaining the restriction is a real barrier to 
> > deployment. There is no *semantic* reason for the distinction.
> 
> W.r.t. the domains, the interaction between the concept language and
> the built in datatype predicates is at best unpleasant and may even
> lead to undecidability (no definitive result at present). I also don't
> believe that this is "a real barrier to deployment" (can you show me
> examples where users really need objects that are both individuals and
> data values?).

Fair question. It comes up quite a bit in my work.
I don't make any claims about 'individuals'; but
I need to have UnambiguousProperty's that
take literal values.

For example, U.S. states that have the same 2-letter
postal code are the same state. So if I know

  :stateCode a ont:UnambiguousProperty.

  _:x :stateCode "KS".
  _:x :population "2688418".

  _:y :stateCode "KS".
  _:y :stateBird :WesternMeadowlark.

then I should be able to conclude

  _:z :population "2688418".
  _:z :stateBird :WesternMeadowlark.


Full details, with namespaces spelled out and all that, in:
  http://www.w3.org/2002/03owlt/sameStateP.rdf
  http://www.w3.org/2002/03owlt/sameStateC.rdf


> I believe that a much bigger barrier to deployment
> would be devising a language where complete (and perhaps even sound)
> reasoners were difficult or impossible to build.

Yes, well, we disagree on that.
Perhaps it belongs in the issues list? I don't see
it there.

http://www.w3.org/2001/sw/WebOnt/webont-issues.html

It is in the list of objectives.

  Effective decision procedure
  http://www.w3.org/TR/2002/WD-webont-req-20020307/#section-objectives

Perhaps that's enough? or perhaps each objective should
have a corresponding issue?

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 23 April 2002 19:30:17 GMT

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