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Re: a bnode URI scheme?!

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 11 Mar 2004 21:49:41 -0500
Message-Id: <200403120249.i2C2nf2E022545@roke.hawke.org>
To: Adam Souzis <adam-l@souzis.com>
Cc: www-rdf-interest@w3.org


> Consider the address bnode example in the RDF Primer 
> (http://www.w3.org/TR/2004/REC-rdf-primer-20040210/#structuredproperties).
> There may be times when you want to reference that address externally 
> (e.g. from another model) but the common sense approach to enable that 
> by just replacing the bNode with a URI reference has a couple of problems:
> * it changes the meaning of the model: bNodes serve as existential 
> variables -- if you replace two distinct bNodes x and y with 2 different 
> URIs you are adding information to the model: because there is nothing 
> in the model that says x and y might not be equal but the two URIs that 
> replace are indeed not equal (since RDF uses intensional semantics for 
> URIs).

Not true.   

I think you're saying 

<a> <b> <c>.
<d> <e> <f>.

entails

<a> owl:differentFrom <d>.

... but I really don't think that's the case.  Can you find some
supporting text?

(My recommendation: bNodes are a real pain to reason about, so avoid
them unless doing so is an even bigger pain.)

       -- sandro
Received on Thursday, 11 March 2004 21:49:00 UTC

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