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LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July 25 telecon)

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 24 Jul 2002 10:24:53 -0400
Message-Id: <p05111700b96466d2c7c6@[10.0.1.4]>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: webont <www-webont-wg@w3.org>

At 2:25 PM +0100 7/24/02, Ian Horrocks wrote:
>On July 24, Jim Hendler writes:
>>
>>  Apologies, won't be able to get full agenda out until late tonight -
>>  here is draft agenda:
>
>I wont be able to make the telecon as I am at ECAI and will be
>chairing a session at that time.
>
>I don't know if it is allowed, but can I:
>
>1. vote for Manchester in the f2f5 straw poll :)
>
>2. vote against closing issue 4.6 as it is closely tied to issue 5.19
>(classes as instances), which is very much open.
>

Ian -
  I was working on this when your email came:

CLOSING OF ISSUE 4.6 (EquivalentTo)

I believe there are two issues tied together in issue 4.6 
(equivalentTo) one is the issue as to whether we have an equivalentTo 
construct that is simply syntactic sugar for sameClass, sameProperty, 
or sameInstance; or whether we had an equivalentTo that allowed 
classes to be made equivalent to properties and instances etc.
  I was one of the stronger proponents for the inclusion of 
equivalentTo, but had assumed it would not be used for these sorts of 
cross area mappings - having seen that this was the case, I am 
willing to remove the construct -- I believe that this is a very 
confusing way of doing classes as instances, and if this construct is 
causing confusion (as I now believe it is) I don't advocate keeping 
it as it makes the language more ambiguous

  So what I will propose is that we REMOVE the equivalentTo property 
from OWL, but keep sameClassAs, etc.   In doing so we do NOT close 
issue 5.19 (Classes as instances) and if we decide to include that in 
the language, then we develop a new, and less ambiguous construct, to 
do that.

Proposed:
  I propose that we CLOSE issue 4.6 with the following resolution:

We will remove the single construct "equivalentTo" from the language, 
as it is possible to use other features (sameClassAs, samePropertyAs, 
sameIndividualAs) to achieve its primary effect.
  equivalentTo has also been used by some people for the mapping of 
classes to instances.  The closing of this issue does not rule out 
the possibility of providing the ability for classes to be used as 
instances -- that is a separate issue (link to issue 5.19) to be 
resolved separately.

Test case: a test case will be proposed in which use of equivalentTo 
maps to an error - cf. Jeremy Carroll's tests for the removed "Q" 
constructs.



-- 
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 Wednesday, 24 July 2002 10:25:11 GMT

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