- From: Pierre-Antoine Champin <swlists-040405@champin.net>
- Date: Thu, 04 Dec 2008 11:11:53 +0000
- 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. >> >> >> >> > > ------------------------------------------------------------ > IHMC (850)434 8903 or (650)494 3973 > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile > phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > >
Received on Thursday, 4 December 2008 11:12:39 UTC