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Re: revised version of semantics document

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Thu, 22 Aug 2002 13:49:16 +0200
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-webont-wg@w3.org
Message-ID: <OFC517682D.84518A7D-ONC1256C1D.00408465@agfa.be>

[...]

> > and I think it is quite natural to explicitly give
> >   :C owl:intersectionOf ( :Student :Employee ) .
> >
> > as a premis, no?
>
> Not at all.  Why should I have to put this in the premise if I don't 
feel
> like it?  Why should it matter?

OK, fine
if you don't like that, you just write

==== peterP1
@prefix : <university#> .

:John a :Student .
:John a :Employee .
====

and jon's agents somewhere came accross
(remark the unnamed class _:U)

==== jonP1
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix : <university#> .

_:U owl:intersectionOf ( :Student :Employee ) .
====

then you could still OWL-entail

==== peterC1
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix : <university#> .

:John a _:X .
_:X owl:intersectionOf ( :Student :Employee ) .
====

but you would indeed need jonP1
it matters because of
all models of the premis are also models of the conclusion
and no new existentials are introduced in the entailment rules

-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Thursday, 22 August 2002 07:50:02 GMT

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