- From: Rinke Hoekstra <hoekstra@uva.nl>
- Date: Wed, 21 May 2008 10:28:49 +0200
- To: <gstoil@image.ece.ntua.gr> <gstoil@image.ece.ntua.gr>
- Cc: schneid@fzi.de, public-owl-wg@w3.org
Yes, I agree it will be incomplete, but I don't think that would be a bad thing, necessarily. My idea was certainly not to iterate all equivalencies, but just some obvious ones that non-expert users tend to overlook. Give them a couple of hints, and they'll figure out the rest for themselves. -Rinke On 21 mei 2008, at 10:20, <gstoil@image.ece.ntua.gr> <gstoil@image.ece.ntua.gr > wrote: > > 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 >> ----------------------------------------------- >> >> > ----------------------------------------------- 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 08:29:34 UTC