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

From: Alan Wu <alan.wu@oracle.com>
Date: Thu, 22 May 2008 13:21:28 -0400
Message-ID: <4835AB98.9040006@oracle.com>
To: Rinke Hoekstra <hoekstra@uva.nl>
CC: "<gstoil@image.ece.ntua.gr>" <gstoil@image.ece.ntua.gr>, schneid@fzi.de, public-owl-wg@w3.org

Rinke,

Second this. A description of some obvious ones can definitely help 
users better understand the language.

Zhe

Rinke Hoekstra wrote:
>
> 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 Thursday, 22 May 2008 17:22:58 GMT

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