Re: asymmetric VS non-symmetric

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

Received on Wednesday, 5 August 2009 07:41:02 UTC