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Re: asymmetric VS non-symmetric

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Tue, 4 Aug 2009 22:48:15 +0100
Message-Id: <0FA108A8-4ADF-4D43-A1DF-45E38E1AEB84@comlab.ox.ac.uk>
Cc: Antoine Zimmermann <antoine.zimmermann@deri.org>, W3C OWL Working Group <public-owl-wg@w3.org>
To: Christine Golbreich <cgolbrei@gmail.com>
Can we have a diff please.

Thanks,
Ian


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
>
Received on Tuesday, 4 August 2009 21:49:01 GMT

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