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Re: get rid of the semantics for RDF?

From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Date: Tue, 20 Dec 2011 10:59:18 +0100
Message-ID: <4EF05C76.8080400@emse.fr>
To: public-rdf-wg@w3.org
Le 19/12/2011 21:11, Richard Cyganiak a écrit :
> Hi Sandro,
> On 19 Dec 2011, at 05:35, Sandro Hawke wrote:
>> On Sat, 2011-12-17 at 12:51 -0500, Kingsley Idehen wrote:
>>> On 12/17/11 12:21 PM, Pat Hayes wrote:
>>>> That is why we are stuck. This situation cannot be resolved
>>>> simply by letting it all hang out. We could simply declare that
>>>> RDF has no semantics, and is simply to be used by programmers
>>>> to mess around with in ways they find handy. Really, this might
>>>> be the best way to move forward. But until we do this, we have
>>>> to take the semantics seriously.
>>> +1
>> The promise of the formal semantics of RDF, I think, is that we'll
>> be able to merge knowledge.
>> If I say something, using decontextualized true statements, and you
>> do the same, using the same vocabulary, then someone can just merge
>> the graphs to have the aggregate knowledge of both of us.   That's
>> pretty cool.   (I wish it worked more often, ... but I have some
>> faith the situation is improving.)
> Is there some factual evidence that the formal semantics actually
> contributes towards this goal of merging knowledge?
> If the formal semantics were relegated to an informative background
> document, and replaced with a different normative document whose
> purpose is merely to define entailment rules between RDF graphs, how
> would you see this hampering the merging of knowledge?

That would be ridiculous. The rules would simply translate the formal 
semantics in a way that leaves little choice on how to implement a 
reasoner, and people who would like to implement it in a different way 
(e.g., with graph homomorphisms for instance) would have to rewrite the 
formal semantics to prove that they do the job correctly. So eventually, 
the formal semantics would be written again, and it would need be 
standardised. That's the whole point of having the model-theoretic 
semantics, it's independent of the implementation and it's elegant, IMHO.

Honestly, I find it make real sense to say that a class represents a set 
of things, much more than:

x subclass y . y subclass z . |- x subclass z .
x subclass y . a type x . |- a type y .

You could also completely get rid of the semantics, which would allow 
systems to use their own custom interpretations of the terms, but I find 
this really useless and harmful for interoperability.

> All the best, Richard

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 83 36
Fax:+33(0)4 77 42 66 66
Received on Tuesday, 20 December 2011 10:13:45 UTC

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