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

Re: TEST: Re: notes for 6/6 until 1:10 (oneOf/sameClassAs)

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 07 Jun 2002 18:36:10 -0400
To: connolly@w3.org
Cc: jos.deroo.jd@belgium.agfa.com, www-webont-wg@w3.org
Message-Id: <20020607183610B.pfps@research.bell-labs.com>

From: Dan Connolly <connolly@w3.org>
Subject: Re: TEST: Re: notes for 6/6 until 1:10 (oneOf/sameClassAs)
Date: 07 Jun 2002 01:17:52 -0500

> 
> On Thu, 2002-06-06 at 17:31, Jos De_Roo wrote:
> > 
> > [...]
> > 
> > > 3d) Proposal to close issue 2.4 - Enumerated Classes (daml:oneOf)
> > > issue:
> [...]
> > > Dan will reconsider a test case posted by Jos.
> > 
> > that is actually the one in
> > http://lists.w3.org/Archives/Public/www-webont-wg/2002May/0276.html
> > "TEST: sameClassAs testcase" [1][2][3]
> 
> i.e. from nothing, conclude:
> 
> [ owl:oneOf ( :a :a :b ) ] owl:sameClassAs [ owl:oneOf ( :b :a :a ) ] .
> 
> 
> Well, my position on 5.10-DAML+OIL-semantics-is-too-weak
>   http://lists.w3.org/Archives/Public/www-webont-wg/2002May/0235.html
> is that OWL shouldn't entail the existence of any
> classes from an empty premise.

What about owl:Thing and owl:Nothing (or daml:Thing and daml:Nothing if you
prefer)?

> i.e. there shouldn't be any axioms with existentials in
> the conclusions. (there's a name for that fragment of FOL, no?
> is that horn clauses? I often forget).

This is certainly not Horn.  In any case existentials in conclusions, even
if this made sense, is different from not entailing the existend of any
classes from an empty premise.

> So I'm currently against rules such as:
>   { :rule9o1 . ?L owl:item ?x } log:implies { ?x a [ owl:oneOf ?L ] } .
> from
>   http://www.agfa.com/w3c/euler/owl-rules

Well, I am definitely for such rules.  (Well, actually, I'm neither for nor
against rules per se, but I am definitely for this sort of entailment.)

[...]

> 
> -- 
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
> 

peter
Received on Friday, 7 June 2002 18:36:23 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:50 GMT