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RE: problems with concise bounded descriptions

From: <Patrick.Stickler@nokia.com>
Date: Fri, 1 Oct 2004 14:42:16 +0300
Message-ID: <1E4A0AC134884349A21955574A90A7A50ADCFC@trebe051.ntc.nokia.com>
To: <pfps@research.bell-labs.com>, <eric@w3.org>
Cc: <www-rdf-interest@w3.org>



> -----Original Message-----
> From: www-rdf-interest-request@w3.org
> [mailto:www-rdf-interest-request@w3.org]On Behalf Of ext Peter F.
> Patel-Schneider
> Sent: 01 October, 2004 12:46
> To: eric@w3.org
> Cc: www-rdf-interest@w3.org
> Subject: Re: problems with concise bounded descriptions
> 
> 
> 
> From: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
> Subject: Re: problems with concise bounded descriptions
> Date: Fri, 01 Oct 2004 05:24:57 -0400 (EDT)
> 
> > From: "Eric Prud'hommeaux" <eric@w3.org>
> > Subject: Re: problems with concise bounded descriptions
> > Date: Thu, 30 Sep 2004 22:17:32 -0400
> 
> [...]
> 
> > > > Problem 7:  This definition does not provide enough 
> information to
> > > > distinguish the node from other distinguishable nodes 
> in the graph.
> > > > Consider, for example, the RDF graph: 
> > > > 	ex:r rdf:type owl:InverseFunctionalProperty .
> > > > 	_:a ex:r _:b .
> > > > 	_:b ex:r _:a .
> > > > 	_:a ex:s "NODE A" .
> > > > 	_:b ex:s "NODE B" .
> > > > Then the CBD of _:a in this graph is
> > > > 	_:x1 ex:r _:x2 .
> > > > 	_:x2 ex:r _:x1 .
> > > > which is the same as the CBD of _:b in this graph but 
> _:a and _:b are
> > > > distinguishable in the graph and thus should have 
> different CBDs.
> > > 
> > > Yeah, but nothing else sovles that either. They're 
> ambiguous to the
> > > server and they're ambiguous to the client. The only 
> additional info
> > > that the server has is that there exists in the domain of 
> discourse
> > > another bNode. I don't think it's worth telling the 
> client about it.
> > 
> > The whole point in this example is that _:a and _:b are *not*
> > distinguishable to the server.  _:a is "NODE A" and _:b is 
> "NODE B".  As
> > the two nodes are distinguishable to the server, they 
> should have different
> > CBDs.
> 
> Arghh!  I meant:
> 
> The whole point in this example is that _:a and _:b *are* 
> distinguishable
> to the server.  _:a is "NODE A" and _:b is "NODE B".  As the 
> two nodes are
> distinguishable to the server, they should have different CBDs.

I'm sorry, but I don't see why any such requirement
would exist.

What does it matter if the CBDs of two resources are the same
graph?

Aside from the fact that one agent cannot request from
another resource a CBD of a resource denoted solely by
an anonymous node.

If we modified your example to one using URIrefs:

   ex:a ex:r ex:b .
   ex:b ex:r ex:a .
   ex:a ex:s "NODE A" .
   ex:b ex:s "NODE B" .

then the CBD of ex:a is

   ex:a ex:r ex:b .
   ex:a ex:s "NODE A" .

and the CBD of ex:b is

   ex:b ex:r ex:a .
   ex:b ex:s "NODE B" .

which are distinct; and also some agent X needing a 
CBD of ex:a or ex:b can ask some other agent Y which
may know something about those resources.

Patrick
Received on Friday, 1 October 2004 11:42:51 GMT

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