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Re: OWL semantics

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Tue, 6 Aug 2002 17:42:54 +0200
To: "Christopher Welty" <welty@us.ibm.com>
Cc: Ian Horrocks <horrocks@cs.man.ac.uk>, www-webont-wg@w3.org
Message-ID: <OFC0A88550.FC7376C3-ONC1256C0D.0054B75C@agfa.be>

Chris,

> Jos,
>
> I believe it's fairly safe to say "it may be impossible."  That is not a
> claim that it IS impossible, it is merely a claim that those of us who
> BELIEVE it is impossible await an existence proof from those who don't.

fair enough (just read his words as "... that it *is* ... impossible ...")

> If you want to make Ian change his language, I suggest you offer a 
proof.
> Even an idea of how it might be done would be a start.

right
I'm trying working out one using Euler in --think mode
and somehow along the lines of
  the proof of all proofs of ?s ?p ?o
  given an owl-theory.n3 should be a fixed-point
my motivation is
  that machines can help us a lot in these
  that we can have no comprehension axioms (maybe)
but I'm not yet there ;-)

-Jos

> -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: +1 914.784.6078, Email: welty@us.ibm.com
>
>
>
>
>
> "Jos De_Roo" <jos.deroo.jd@belgium.agfa.com>
> Sent by: www-webont-wg-request@w3.org
> 08/05/2002 08:02 PM
>
>
>         To:     Ian Horrocks <horrocks@cs.man.ac.uk>
>         cc:     www-webont-wg@w3.org
>         Subject:        Re: OWL semantics
>
>
>
>
> [only a very partial reply]
>
> [...]
>
> > It is also worth pointing out that such axiomatisations are invariably
> > large and complex, and that it is difficult/impossible to be sure that
> > they are correct. E.g., take a look at the axiomatisation of
> > DAML+OIL/RDF in [3], which contains around 140 axioms. FOL reasoners
> > can be used to detect "obvious" inconsistencies (as happened with
> > earlier versions of [3]), but simply ironing these out is a LONG way
> > from proving that the axiomatisation correctly captures the meaning of
> > the language.
>
> that is not enough to suggest a
>   "impossible to be sure that they are correct"
> let's just call it difficult/challenging
> engineering and no more
>
> -- ,
> Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Tuesday, 6 August 2002 11:43:32 GMT

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