W3C home > Mailing lists > Public > www-webont-wg@w3.org > March 2002

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

From: Dan Connolly <connolly@w3.org>
Date: 21 Mar 2002 17:22:50 -0600
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: Libby Miller <Libby.Miller@bristol.ac.uk>, "Peter F. "Patel-Schneider <pfps@research.bell-labs.com>, webont <www-webont-wg@w3.org>
Message-Id: <1016752971.26064.147.camel@dirk>
On Thu, 2002-03-21 at 14:28, Ian Horrocks wrote:
> 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

I gather when you say "OWL reasoner" you mean a complete
reasoner.

I'm not very interested in such a thing.

Regular old horn-clause/datalog reasoners
(with some built-in predicates like
string:lessThan and such) seem
to get me what I need pretty well.

So this argument about negation and complete reasoning
doesn't persuade me that we should keep R and V disjoint.

> - 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
> > 
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Thursday, 21 March 2002 18:23:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:48 GMT