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Re: Missing AllSame

From: Ron Alford <ronwalf@wam.umd.edu>
Date: Fri, 20 Jun 2003 13:42:00 -0400 (EDT)
To: Guus Schreiber <schreiber@swi.psy.uva.nl>
cc: public-webont-comments@w3.org
Message-ID: <Pine.LNX.4.44.0306201336570.25412-100000@volus.net>

Hello,
I'm satisfied with this reponse.

-Ron
  
On Thu, 19 Jun 2003, Guus Schreiber wrote:

> Ron Alford wrote:
> http://lists.w3.org/Archives/Public/public-webont-comments/2003May/0070.html
> 
>  > Hello,
>  > Since there is an owl:AllDifferent, why is there not an owl:AllSame? 
>   I have a need for it on my current project.  It would be nice for it 
> to have similar semantics to owl:AllDifferent.
>  >
>  > Thanks,
>  >   - Ron Alford
>  >
>  > --
>  > Ron Alford, KB0NUV
>  > http://volus.net/~ronwalf
> 
> 
> Ron,
> 
> Thanks for your comment.
> 
> We introduced a AllDifferent construct because of the exponential growth 
> of the number of differentFrom statements; see Sec. 6.3 of OWL Reference [1]
> 
> [[
> For ontologies in which the unique-names assumption holds, the use of 
> owl:differentFrom is likely to lead to a large number of statements, as 
> all individuals have to be declared pairwise disjoint.
> ]]
> 
> The case is different for sameAs, because sameAs only leads to linear 
> growth of the number of statements. (due to the transitive nature of 
> sameAs, the statements "a sameAs b" and "b sameAs c" already imply "a 
> sameAs c").
> 
> Please respond, copying public-webont-comments@w3.org, as to whether
> you are satisfied with this response.
> 
> Guus Schreiber
> 
> 
> [1] http://www.w3.org/TR/owl-ref/#AllDifferent-def
> 
> 

--
Ron Alford, KB0NUV
http://volus.net/~ronwalf
Received on Friday, 20 June 2003 13:42:06 GMT

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