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Re: AllDisjoint in RDF mapping

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 23 Feb 2007 11:31:51 -0600
Message-Id: <p06230905c204d509e883@[]>
To: Jim Hendler <hendler@cs.umd.edu>
Cc: public-owl-dev@w3.org

>At 10:44 AM -0500 2/23/07, ewallace@cme.nist.gov wrote:
>>Jim Hendler wrote:
>>>Let me join Matthew in requesting this - note also that
>>>"DisjointUnion" doesn't answer this need in all cases - often we want
>>>to make things disjoint that either belong to many different classes
>>>or that we have disjunction of classes without wanting to imply that
>>>it is in some way complete.
>>>   -JH
>>+1  on adding an AllDisjoint construct
>>DisjointUnion supports a common pattern used in a number of modeling
>>languages (including UML and EXPRESS), and no one from WebOnt would be
>>surprised that I am in favor of including it in OWL 1.1.  However, just
>>as Jim points out, there are many cases where one wants to specify
>>disjointness across a set of classes which don't make up a complete
>>covering.  Many new OWL users are surprised that classes aren't disjoint by
>>default.  Once they get over this, they start looking for constructs in
>>the language like DisjointUnion and AllDisjoint.
>actually, I do have a little problem with disjointUnion - the 
>problem is that this would be the first OWL feature (I think) that 
>combines two definitions at the same time -- so if I say
>Class A == DisjointUnion (B,C,D)     (with the obvious meaning, no 
>syntax implied)
>then I am asserting both the definition of Class A AND the fact that 
>B,C, and D are disjoint.  From a human point of view, I wonder if it 
>isn't better to avoid the syntactic sugar and have this remain as 
>two assertions
>Class A= Union(B,C,D)
>just seems to me that the clarity in the modeling would be clearer



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Received on Friday, 23 February 2007 17:32:12 UTC

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