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RE: ISSUE-125 (min1some): Min 1 QCR = someValuesFrom - Serialize as someValuesFrom?

From: <gstoil@image.ece.ntua.gr>
Date: Wed, 21 May 2008 08:20:38 -0000
Message-Id: <200805210820.m4L8KcNF011242@manolito.image.ece.ntua.gr>
To: schneid@fzi.de, hoekstra@uva.nl
Cc: public-owl-wg@w3.org


Hi,

I am afraid that this attempt is deemed to be incomplete. 

Then why not also mention the equivalence between maxQualifiedCardinality(0 R
(complementOf C)) and allValuesFrom( R C )? And then why not transitiveRole(R)
and subPropertyOf(subPropertyChain (R R) R)? And why not ...

-gstoil

> -----Original Message-----
> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org]
> On Behalf Of Rinke Hoekstra
> Sent: Wednesday, May 21, 2008 10:12 AM
> To: Michael Schneider
> Cc: OWL Working Group WG
> Subject: Re: ISSUE-125 (min1some): Min 1 QCR = someValuesFrom - Serialize
> as someValuesFrom?
> 
> 
> Hi,
> 
> I suppose, the least we could do is add a short description of some of
> these equivalencies to the Primer. For instance at [1] to mention the
> equivalence between minCardinality and someValuesFrom. And at [2] to
> say something about equivalentTo vs. subClassOf. Conversely, some
> notions seem intuitively equivalent, but are not, such as functional
> properties and exactly 1 cardinality restrictions.
> 
> -Rinke
> 
> [1]
> http://www.w3.org/2007/OWL/wiki/Primer#Adescriptionobjectpropertymincardin
> ality
> [2] http://www.w3.org/2007/OWL/wiki/Primer#Aclassequivalentto2way
> 
> On 20 mei 2008, at 22:00, Michael Schneider wrote:
> 
> > I strongly concur with Bijan's points, and want to add a few more.
> >
> > First, I have to apologize to discuss this topic while the issue is
> > still in
> > "raised" state. But I cannot attend tomorrow's telco (travelling to
> > Romania),
> > so I am going to say, what I would say there, here.
> >
> > It is intended that OWL provides different ways to express
> > semantically
> > equivalent things, because OWL is not only a reasoning formalism,
> > but also a
> > modeling language. That's why we now have owl:disjointUnion, which
> > gives
> > additional modeling power to OWL 2 in exchange for forward-
> > compatibility, and
> > without enhancing the semantic expressivity of the language.
> >
> > OWL 1, btw., also contains a lot of syntactic sugar:
> > owl:equivalentClass can
> > be substituted by two rdfs:subClassOf axioms, which would bring
> > certain OWL 1
> > ontologies nearer to RDFS. Or there is owl:AllDifferent, or HasValue
> > restrictions. Even owl:sameAs can be expressed by means of a nominal-
> > based
> > class assertions.
> >
> > For the case of >=1-QCRs vs. SomeValues-restrictions: These are pretty
> > different modeling tools, which just happen to be equivalent
> > technically. For
> > example, it might make sense, from a modeling perspective, to
> > explicitly
> > express [1..*] relationships between two classes, or even [0..*]
> > relationships, although the latter would be redundant technically.
> > Making
> > these features illegal in OWL, and demanding to circumscribe them in a
> > technically equivalent way, would not be what I want in such a case.
> > Actually,
> > this would be the situation of pre-OWL-2, where it was well known
> > how to
> > circumscribe QCRs. But people asked for QCRs often enough, anyway,
> > probably
> > not without a reason.
> >
> > Even worse than disallowing >={0|1)-QCRs would it be to demand from
> > the OWL
> > tools do the transformation themselves. I just try to compare this
> > with the
> > strange situation where my Java programming IDE would rewrite all my
> > generics,
> > autoboxing, non-indexed loops, and all the other stuff which does
> > not go into
> > the bytecode eventually, just in order to make it more Java-1.0
> > compatible. I
> > would certainly not use this IDE ever again. :) And then I try to
> > imagine
> > Topbraid Composer, which would have to serialize my >=1-QCR silently
> > into a
> > SomeValues-restriction. I expect this would probably lead to a lot
> > of traffic
> > in Holger's mailing list... :-/
> >
> > Cheers,
> > Michael
> >
> >> -----Original Message-----
> >> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org
> >> ]
> >> On Behalf Of Bijan Parsia
> >> Sent: Monday, May 19, 2008 10:37 PM
> >> To: OWL Working Group WG
> >> Subject: Re: ISSUE-125 (min1some): Min 1 QCR = someValuesFrom -
> >> Serialize as someValuesFrom?
> >>
> >>
> >> So:
> >> 	1) intention hiding and non-roundtrippable; plus it frustrates the
> >> hell out of users when you silently change what they wrote
> >> 	2) non-orthogonal; we need the general form in order to handle
> >> larger cardinalities anyway, so would have to impose a rather strange
> >> restriction
> >> 	3) unnecessary; if users want to write their ontologies this way
> >> (so
> >> as to be compatible) then can easily do so, or postprocess.
> >> Furthermore, you could have a preprocessor before your old tool that
> >> did this, no need to build in this kind of strangeness into the base
> >> language.
> >>
> >> I propose closing this, with no change, on these grounds. I don't
> >> think we need to note the equivalence in the spec either (there are
> >> lots of equivalences...I don't see why this one is particularly
> >> interesting).
> >>
> >> Cheers,
> >> Bijan.
> >
> 
> -----------------------------------------------
> Drs. Rinke Hoekstra
> 
> Email: hoekstra@uva.nl    Skype:  rinkehoekstra
> Phone: +31-20-5253499     Fax:   +31-20-5253495
> Web:   http://www.leibnizcenter.org/users/rinke
> 
> Leibniz Center for Law,          Faculty of Law
> University of Amsterdam,            PO Box 1030
> 1000 BA  Amsterdam,             The Netherlands
> -----------------------------------------------
> 
> 
Received on Wednesday, 21 May 2008 08:21:32 GMT

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