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Re: LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July 25 telecon)

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Thu, 25 Jul 2002 01:22:38 +0200
To: Dan Connolly <connolly@w3.org>
Cc: Jonathan Borden <jonathan@openhealth.org>, "Peter F. "Patel-Schneider <pfps@research.bell-labs.com>, www-webont-wg@w3.org
Message-ID: <OFE3216CF8.4D2BA1DF-ONC1256C00.007F6122@agfa.be>

[...]
> Well, an approach where the above passes just involves
> the RDF Core model theory plus a few horn-clause rules:
>
> { :x = :y } log:implies { :y = :x }. # symmetric
> { :x = [ = :z] } log:implies { :x = :z }. # transitive
> { :x :p :y. :x = :z. } log:implies { :z :p :y }.
> { :x :p :y. :p = :q. } log:implies { :x :q :y }.
> { :x :p :y. :y = :z. } log:implies { :x :p :z }.

fully agreed

> (taken from http://www.w3.org/2000/10/swap/test/sameThing.n3,
> lightly edited)
>
>
> My experience with this approach is pretty positive.
> Our implementation is kinda slow, but it's tolerable.
>
>
> I don't have any experience with an approach where
> that test doesn't work.
>
>
> [hmmm... Jos, I see a rule for reflexivity of
> equivalentTo in
>   http://www.agfa.com/w3c/euler/owl-rules
> but not one for transitivity nor symmetry,
> let alone substitution-of-equals-for-equals.].

[I've added those, but we have indeed trouble
with on-the-fly substitution-of-equals-for-equals...
right now we have a pre-flight one, but we should
definitely have a more dynamic unification method...]

-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Wednesday, 24 July 2002 19:23:20 GMT

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