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Re: SEM: semantics for current proposal (why R disjoint V?)

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Thu, 21 Mar 2002 20:28:59 +0000
Message-ID: <15514.17035.384988.409239@oaklands.demon.co.uk>
To: Libby Miller <Libby.Miller@bristol.ac.uk>
Cc: Dan Connolly <connolly@w3.org>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, webont <www-webont-wg@w3.org>
On March 21, Libby Miller writes:
> >
> > As noted in the design discussions for DAML+OIL, I don't
> > see sufficient justification for making V disjoint
> > from R.
> >
> > It seems silly not to be able to talk about the intersection
> > of two sets of strings, or UniqueProperty's whose
> > range is dates, or whatever.

This means that any OWL reasoner has to take on responsibility for
reasoning about types - which could be a major implementation overhead
(there are also some technical reasons related to negation - full
details can be found in [1]). The current design means that all this
can be delegated to a "type system" (the details of which we don't
need to consider in OWL).

[1] http://www-lti.informatik.rwth-aachen.de/~clu/papers/archive/lutzdiss.pdf

> >
> 
> I agree. It's very counter-intuitive to separate them out. I ran into a
> lot of problems with this, creating a daml schema for icalendar.

An example would be useful here.

Ian

> 
> libby
> 
Received on Thursday, 21 March 2002 15:30:56 GMT

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