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Re: Minimal dataset semantics

From: Richard Cyganiak <richard@cyganiak.de>
Date: Fri, 24 Aug 2012 11:52:28 +0100
Cc: RDF Working Group WG <public-rdf-wg@w3.org>, Antoine Zimmermann <antoine.zimmermann@emse.fr>
Message-Id: <EAD18E67-99A5-4848-AFB0-0F861701C5AE@cyganiak.de>
To: Ivan Herman <ivan@w3.org>

On 24 Aug 2012, at 11:16, Ivan Herman wrote:
>> So the second sentence rules out any semantic extensions that make a dataset's truth dependent on the content of some named graph, right?
> No. At least that is certainly not the intention, though maybe the formalization in English is not ideal.

Okay. Let me make a meta-comment. It's difficult to talk about semantics in anything but mathematics. All the interest is in the details, and the details require formal maths. Sketching a semantics in English is counter-productive IMO. For sketching, test cases are much better than English IMO.

We can always show some datasets and tell if the relationship between them is entailment, non-entailment, equivalence, or contradiction. I think that would be a decent way of making progress, actually.

> (I presume that, in your argumentation, a=b and a≠b means in the sense of mutually inferring through simple entailment.)

No; it meant equality and non-equality, in the standard mathematical sense. But anyways, yeah, I think that the mathematics do not say what you mean to say, but I think I understand what you mean to say.

> Antoine provided some sort of a short sentence of what is happening:
> "All RDF graphs in an RDF dataset don't mean the same thing. To be explicit about what they mean, we provide a vocabulary that specify the semantics of each graph. We call the semantics assigned to a <name,graph> pair its entailment regime, because it determines what entailments are valid for that pair. For example ..."

I won't support a proposal that involves vocabulary for selecting the semantics on a per-graph basis. This is *much* too complicated for my taste.

> Personally, I am little bit afraid of the complexity of the thing to be honest. Hence it may not fly.


Received on Friday, 24 August 2012 10:52:56 UTC

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