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Re: Mapping to RDF Graphs and reification

From: Pierre-Antoine Champin <swlists-040405@champin.net>
Date: Thu, 04 Dec 2008 11:11:53 +0000
Message-ID: <4937BAF9.3090405@champin.net>
To: Pat Hayes <phayes@ihmc.us>
CC: Bijan Parsia <bparsia@cs.man.ac.uk>, public-owl-dev@w3.org, Daniel Mahler <dmahler@gmail.com>, Jeff Thompson <jeff@thefirst.org>

Pat Hayes a écrit :
> Well, someone could argue that since the negation construction involves
> meta-description, iterating it gives you a kind of truth predicate, in a
> sense. Kinda. But Tarski's paradox doesn't arise for other reasons,
> having to do with how impoverished RDF is as an expressive logic.

Wouldn't

 _:x rdf:type owl:NegativePropertyAssertion
 _:x owl:sourceIndividual _:x
 _:x owl:assertionProperty owl:sourceIndividual
 _:x owl:targetIndividual _:x

a perfect example of that paradox (in OWL Full, of course) ?

What am I missing?

  pa

> To get
> Tarski's construction to work, the logic has to be able to describe its
> own grammar and its own notion of provability, which takes a certain
> minimal degree of expressivity involving quantifiers that RDF does not
> come anywhere near. (If you move to the more expressive logic being
> encoded in the RDF syntax - the one with negation - then it no longer
> uses reification in the same way: RDF reification doesn't reify /that/
> logic's syntax.)
> 
> Pat
> 
> 
>> For the non-Full part, this is just syntax. It is just ugly syntax for
>> "not(s p o)".
>>
>> Even if full, in some sense, most of the time, it's just syntax. The
>> story is much more complex because it's also denoting objects in the
>> domain and potentially could reflect on the syntax, yadda yadda, but
>> that's no worse than anything else, really.
>>
>>> (I asked this question question on a w3 rdf list many years ago
>>> and I still do not know)
>>
>>
>> Well, I hope you do now :)
>>
>> Cheers,
>> Bijan.
>>
>>
>>
>>
> 
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Received on Thursday, 4 December 2008 11:12:39 GMT

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