Re: asymmetric VS non-symmetric

On 4 sep 2009, at 11:37, Ian Horrocks wrote:
> "Note that being asymmetric is a much stronger notion than being non- 
> symmetric;
> likewise, being symmetric is a much stronger notion than being non- 
> asymmetric.
> Moreover, asymmetry is a stronger notion than anti-symmetry as it  
> requires that
> the relationship is also irreflexive."

Works for me.

Rinke


>
> I agree with Uli's point that the primer needs to be kept short and  
> shouldn't be expected to "provide exhaustive clarifications of all  
> subtleties and explanations of all possible misunderstandings".  
> However, I can live with the above modest expansion if others can.
>
> Ian
>
>
>
> On 4 Sep 2009, at 09:20, Rinke Hoekstra wrote:
>
>> Hi,
>>
>> Guess I agree with both of you ;)
>>
>> On 3 sep 2009, at 14:34, mark@few.vu.nl wrote:
>>> "Note that asymmetry is a stronger notion than anti-symmetry as it  
>>> requires that
>>> the relationship is also irreflexive."
>>
>> That looks good.
>>
>>> Create links for the terms "asymmetry", "anti-symmetry" and  
>>> "irreflexivity"
>>> (e.g. wikipedia) and it's what I would need from a "primer".
>>
>> I disagree. Wikipedia pages tend to change, and are outside the  
>> control of the WG, the W3C, nor subject another trusted editorial  
>> process (as RFC's or ISO).
>>
>> Your proposed wording should be enough.
>>
>> -Rinke
>>
>>>
>>> Regards,
>>> Mark van Assem.
>>>
>>>> Hi Rinke,
>>>>
>>>> yes, one could add more explanation regarding asymmetric properties
>>>> --- but I doubt whether the primer is the right place: it's a  
>>>> *prime*r
>>>> (as in 'first starting point'), and thus won't be the place to  
>>>> provide
>>>> exhaustive clarifications of all subtleties and explanations of all
>>>> possible misunderstandings. I can think of/remember many questions/
>>>> misunderstandings of OWL constructors, and also how they  
>>>> interact, and
>>>> I don't want to see  asymmetric properties being singled out as the
>>>> one feature that is explained in depth...
>>>>
>>>> Cheers, Uli
>>>>
>>>> On 2 Sep 2009, at 15:56, Rinke Hoekstra wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I just had a request from Mark van Assem to add an extra  
>>>>> explanation
>>>>> to the primer about asymmetry.
>>>>>
>>>>> Pascal's addition to the primer [1] is fine:
>>>>>
>>>>> "Note that being asymmetric is a much stronger notion than being  
>>>>> non-
>>>>> symmetric. Likewise, being symmetric is a much stronger notion  
>>>>> than
>>>>> being non-asymmetric. "
>>>>>
>>>>> ... but a bit short and could introduce additional confusion (what
>>>>> then does non-symmetry mean? and non-asymmetric?). Also, it  
>>>>> might be
>>>>> helpful to say something along the lines that asymmetry is anti-
>>>>> symmetry + irreflexivity (anti-symmetry and asymmetry are easily
>>>>> confused).
>>>>>
>>>>> The primer would be the right place for this addition.
>>>>>
>>>>> -Rinke
>>>>>
>>>>> [1]
>>>> http://www.w3.org/2007/OWL/wiki/index.php?title=Primer&diff=25059&oldid=25056
>>>>>
>>>>>
>>>>> On 5 aug 2009, at 09:40, Christine Golbreich wrote:
>>>>>
>>>>>> 2009/8/4 Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>:
>>>>>>> Can we have a diff please.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Ian
>>>>>>
>>>>>>
>>>>>> - for profiles
>>>>>>
>>>>
>>> http://www.w3.org/2007/OWL/wiki/index.php?title=New_Features_and_Rationale&diff=prev&oldid=25076
>>>>>> - for asymmetric
>>>>>>
>>>>
>>> http://www.w3.org/2007/OWL/wiki/index.php?title=New_Features_and_Rationale&diff=prev&oldid=25052
>>>>>>
>>>>>> cg
>>>>>>
>>>>>>
>>>>>>> On 4 Aug 2009, at 18:58, Christine Golbreich wrote:
>>>>>>>
>>>>>>>> Note on asymmetric properties and profiles added in NF&R
>>>>>>>>
>>>>>>>> cg
>>>>>>>> 2009/7/31 Antoine Zimmermann <antoine.zimmermann@deri.org>:
>>>>>>>>>
>>>>>>>>> Dear all,
>>>>>>>>>
>>>>>>>>> Until today, I did not look at the semantics of  
>>>>>>>>> AsymmetricProperty
>>>>>>>>> because
>>>>>>>>> the word was familiar enough to me to intuitively understand  
>>>>>>>>> it.
>>>>>>>>> I was
>>>>>>>>> however wrongly assuming that the word was used to denote non-
>>>>>>>>> symmetric.
>>>>>>>>> From a linguistic perspective, asymmetry is a lack or  
>>>>>>>>> absence of
>>>>>>>>> symmetry.
>>>>>>>>> Some mathematical texts use "asymmetric" to simply mean "not
>>>>>>>>> symmetric".
>>>>>>>>>
>>>>>>>>> I am aware that "asymmetric relation" is often used in
>>>>>>>>> mathematics to
>>>>>>>>> denote
>>>>>>>>> "strongly asymmetric relation", i.e., no pairs of elements are
>>>>>>>>> related in
>>>>>>>>> a
>>>>>>>>> bidirectional (symmetric) way. While it is perfectly ok that
>>>>>>>>> OWL2 defines
>>>>>>>>> AsymmetricProperties the way it does, I am surprised not to  
>>>>>>>>> find
>>>>>>>>> *any*
>>>>>>>>> remark, neither in the formal specs, nor in the UFDs, nor in  
>>>>>>>>> the
>>>>>>>>> mailing
>>>>>>>>> list archives, about the fact that AsymmetricProperty is not  
>>>>>>>>> the
>>>>>>>>> complement
>>>>>>>>> of SymmetricProperty.
>>>>>>>>>
>>>>>>>>> I am sure that other people are understanding asymmetry in the
>>>>>>>>> same way
>>>>>>>>> as I
>>>>>>>>> did, so I'd suggest adding a small sentence in the Primer  
>>>>>>>>> (Sect.
>>>>>>>>> 6.1 [1])
>>>>>>>>> and
>>>>>>>>> NF&R (Sect.2.2.3 [2]) stating that "asymmetric" is not the
>>>>>>>>> negation of
>>>>>>>>> "symmetric". Since the UFDs are still in LC, this should be
>>>>>>>>> addressed
>>>>>>>>> somehow.
>>>>>>>>>
>>>>>>>>> [1]
>>>>>>>>>
>>>>>>>>>
>>>> http://www.w3.org/TR/2009/WD-owl2-primer-20090421/#Property_Characteristics
>>>>>>>>> [2]
>>>>>>>>>
>>>>>>>>> http://www.w3.org/TR/2009/WD-owl2-new-features-20090421/
>>>>>>>>> #F6:_Reflexive.2C_Irreflexive. 
>>>>>>>>> 2C_and_Asymmetric_Object_Properties
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> --
>>>>>>>>> Antoine Zimmermann
>>>>>>>>> Post-doctoral researcher at:
>>>>>>>>> Digital Enterprise Research Institute
>>>>>>>>> National University of Ireland, Galway
>>>>>>>>> IDA Business Park
>>>>>>>>> Lower Dangan
>>>>>>>>> Galway, Ireland
>>>>>>>>> antoine.zimmermann@deri.org
>>>>>>>>> http://vmgal34.deri.ie/~antzim/
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Christine
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> -- 
>>>>>> Christine
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ---
>>>>> Drs Rinke Hoekstra
>>>>>
>>>>> Leibniz Center for Law      |  AI Department
>>>>> Faculty of Law              |  Faculty of Sciences
>>>>> Universiteit van Amsterdam  |  Vrije Universiteit
>>>>> Kloveniersburgwal 48        |  De Boelelaan 1081a
>>>>> 1012 CX  Amsterdam          |  1081 HV Amsterdam
>>>>> +31-(0)20-5253499           |  +31-(0)20-5987752
>>>>> hoekstra@uva.nl             |  hoekstra@few.vu.nl
>>>>>
>>>>> Homepage: http://www.few.vu.nl/~hoekstra
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>>
>> ---
>> Drs Rinke Hoekstra
>>
>> Leibniz Center for Law      |  AI Department
>> Faculty of Law              |  Faculty of Sciences
>> Universiteit van Amsterdam  |  Vrije Universiteit
>> Kloveniersburgwal 48        |  De Boelelaan 1081a
>> 1012 CX  Amsterdam          |  1081 HV Amsterdam
>> +31-(0)20-5253499           |  +31-(0)20-5987752
>> hoekstra@uva.nl             |  hoekstra@few.vu.nl
>>
>> Homepage: http://www.few.vu.nl/~hoekstra
>>
>>
>>
>>
>>
>>
>



---
Drs Rinke Hoekstra

Leibniz Center for Law      |  AI Department
Faculty of Law              |  Faculty of Sciences
Universiteit van Amsterdam  |  Vrije Universiteit
Kloveniersburgwal 48        |  De Boelelaan 1081a
1012 CX  Amsterdam          |  1081 HV Amsterdam
+31-(0)20-5253499           |  +31-(0)20-5987752
hoekstra@uva.nl             |  hoekstra@few.vu.nl

Homepage: http://www.few.vu.nl/~hoekstra

Received on Friday, 4 September 2009 13:46:27 UTC