- From: Natasha Noy <noy@SMI.Stanford.EDU>
- Date: Fri, 22 Oct 2004 17:34:32 -0700
- To: Christopher Welty <welty@us.ibm.com>
- Cc: Alan Rector <rector@cs.man.ac.uk>, ewallace@cme.nist.gov, swbp <public-swbp-wg@w3.org>
Yes, you are right -- sorry. But still you can define direct-instance
?x of ?C in FOL as iff
(forall ?A (=> (and (?C ?x) (?A ?x))
(= ?C ?A)))
Is this wrong again?
Of course this, by itself, has little to do with assymetry of domains
and ranges in OWL and I no longer remember how this came about :)
Natasha
On Oct 22, 2004, at 4:11 PM, Christopher Welty wrote:
>
> OK, in my world A subclassOf B has an FOL interpretation of (=> (A ?x)
> (B ?x)) and o instance-of A has an FOL interpretation of (A o).
> You've invented a new logic on top of FOL, in which the elements of
> the language (i.e. subclass, instance-of) are FOL predicates. I was
> talking about FOL.
>
> -Chris
>
> Dr. Christopher A. Welty, Knowledge Structures Group
> IBM Watson Research Center, 19 Skyline Dr., Hawthorne, NY 10532
> USA
> Voice: +1 914.784.7055, IBM T/L: 863.7055, Fax: +1 914.784.7455
> Email: welty@watson.ibm.com, Web:
> http://www.research.ibm.com/people/w/welty/
>
> public-swbp-wg-request@w3.org wrote on 10/22/2004 06:11:48 PM:
>
> >
> > > Well, OKBC was intended to be an API, in my understanding, so it
> may
> > > very well have capabilities that are beyond FOL, as OO languages
> do.
> >
> > but there is an axiomatization for it in FOL in the specs, AFAIK
> >
> > >
> > > Regarding the axiomatization, why don't you try writing FOL axioms
> > > that capture this. I don't understand how what you have said can
> be
> > > written in FOL.
> >
> > (=> (direct-type ?C ?x)
> > (not (exists ?Y (and (subclass-of ?Y ?C) (instance-of ?X
> ?Y))))
> >
> > (modulo the correct order of arguments for the predicates)
> >
> > > Then, much more to the point, try it in OWL.
> >
> > Ah, that's a whole other story :) But you were generalizing to FOL.
> >
> > Natasha
> >
> >
Received on Saturday, 23 October 2004 00:34:38 UTC