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Re: Draft for a "minimal dataset semantics"

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Wed, 12 Sep 2012 21:08:27 -0400
Message-ID: <5051320B.7080600@gmail.com>
To: Antoine Zimmermann <antoine.zimmermann@emse.fr>
CC: RDF WG <public-rdf-wg@w3.org>
I don't think that example 2.16 is correct.

It seems to me that any dataset with a consistent default graph is consistent.

Any interpretation of the default graph can be extended to an interpretation 
of the dataset by mapping every resource to inconsistent graphs.   This 
trivially satisfies "IGEXT(/I_d /(/n/)) is defined and /E/-entails g" as an 
inconsistent graph entails every graph.

I don't think that this means that 2.16 is not tricky.  There is some 
interaction.  However, this means that named graphs are not independent from 
each other.  In fact, there is a much easier situation showing that named 
graphs are not independent, namely 2.13 T11.2  Similarly, it means that named 
graphs are not independent from the default graph.

It is also the case that an inconsistent default graph makes the named graphs 
irrelevant.

This last is, I think, a particularly strong point against providing this sort 
of semantics at all.


peter
Received on Thursday, 13 September 2012 01:09:00 GMT

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