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

From: Rinke Hoekstra <hoekstra@uva.nl>
Date: Wed, 21 May 2008 10:28:49 +0200
Cc: schneid@fzi.de, public-owl-wg@w3.org
Message-Id: <1EC8A26D-6727-4646-B3C1-E8183E540160@uva.nl>
To: <gstoil@image.ece.ntua.gr> <gstoil@image.ece.ntua.gr>

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 GMT

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