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mergeg in current Semantics ED

From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Date: Thu, 07 Mar 2013 16:52:52 +0100
Message-ID: <5138B7D4.5070404@emse.fr>
To: RDF WG <public-rdf-wg@w3.org>
There is a problem with the definition of merge in the draft.

I'm using math notations instead of a concrete serialisation syntax 
because I want to show things at the abstract syntax level, which is 
what RDF Semantics relies on.

Let us take a blank node b from the set of blank nodes. Let us consider 
the two graphs G1 = {(<s1>,<p1>,b)} and G2 = {(<s2>,<p2>,b)}.

Let us ask ourselves whether {G1,G2} entails:

G = {(<s1>,<p1>,b),(<s2>,<p2>,b)}

The answer is trivially NO wrt the current semantics of the ED.
Yet, reasoners typically would, in this case, merge G1 and G2 to get a 
single graph and work out the non-entailment. However, with the new 
definition of merge, this breaks and fails. Reasoners must standardise 
apart the bnodes and that's what the merge should be.
Antoine Zimmermann
ISCOD / LSTI - Institut Henri Fayol
École Nationale Supérieure des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
Tél:+33(0)4 77 42 66 03
Fax:+33(0)4 77 42 66 66
Received on Thursday, 7 March 2013 15:53:22 UTC

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