- From: Rinke Hoekstra <hoekstra@few.vu.nl>
- Date: Wed, 2 Sep 2009 16:56:53 +0200
- To: OWL 2 <public-owl-wg@w3.org>
- Cc: Mark van Assem <mark@cs.vu.nl>
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
Received on Wednesday, 2 September 2009 14:57:30 UTC