W3C home > Mailing lists > Public > www-webont-wg@w3.org > May 2003

Re: owl:All(something) ??

From: Jim Hendler <hendler@cs.umd.edu>
Date: Mon, 12 May 2003 09:00:08 -0400
Message-Id: <p05200f1bbae54af839a1@[10.0.1.2]>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: webont <www-webont-wg@w3.org>

My bad for forgetting that same was transitive and that we would need 
four constructs.  I can write an answer to that one.

For the person who asked for allDisjoint, can someone see if they can 
find the WG's discussion on this and craft a response?  Any volunteers
  -JH


At 10:14 +0100 5/12/03, Ian Horrocks wrote:
>On May 11, Jim Hendler writes:
>>
>>  We have received a couple of comments that we should have some other
>>  constructs similar to allDifferent
>>    one comment suggest AllSame
>>  another asks for AllDisjoint
>>
>>  we need an answer as to why we included the first and not the latter
>>  two, or we need to decide our current mechanism could be extended to
>>  allow it to be used on other properties  (which would probably not
>>  require another LC if we make it clear this is just a piece of
>>  syntactic sugar since we have the appropriate semantics already).
>
>As Jeremy points out, the various "same" relations are transitive, so
>there is no n^2 blowup in the number of property relationships
>required to express them, and the result is more compact than a (fully
>expanded) list would be.
>
>I also agree with Jeremy's account of the WG's thinking
>w.r.t. disjoint classes - that it is much less frequently required,
>and that the numbers (of classes) involved would typically be small
>(compared to unique individuals). It was therefore decided that
>additional syntax was not justified.
>
>W.r.t. disjoint properties, I'm not sure we even considered it. It is
>rarely asked for, and unlike the class/individual cases it is
>relatively difficult to express in the existing language given
>that we don't have property negation.
>
>Ian
>
>
>
>
>
>>
>>  Any thoughts?




-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
http://www.cs.umd.edu/users/hendler
Received on Monday, 12 May 2003 09:00:29 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:58:00 GMT