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Re: PROPOSAL to *close* (not postpone) ISSUE-83

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Thu, 13 Dec 2007 11:08:01 -0500
Message-Id: <40389D17-05F3-4044-B629-52DC16693507@gmail.com>
Cc: public-owl-wg@w3.org
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>

This was discussed at TC. Action is on me an Ian to draft wording  
explaining closing/relation to OWL Full.
The gist is that it will never be in DL because of undecidability. It  
will be in OWL Full by virtue of syntax. Following precedent of OWL  
1.0 we don't specifically document features outside OWL DL, though  
they may have semantics given in full, and that it will be at the  
discretion of the OWL Full semantics document editor to decide  
whether they want to provide a specific semantics for the form.

On Dec 13, 2007, at 10:05 AM, Peter F. Patel-Schneider wrote:

> Issue-83 asks for property chains on both sides of subproperty axioms.
> As pointed out by Uli Sattler
> http://lists.w3.org/Archives/Public/public-owl-wg/2007Nov/0600.html
> this makes OWL 1.1 undecidable.
> Contrary to what Ian Horrocks says
> http://lists.w3.org/Archives/Public/public-owl-wg/2007Dec/0012.html
> this feature would automatically be in an OWL
> Full version because there would have to be in OWL Full a semantic
> treatment of property chains and then there would be no way of  
> excluding
> them from both ends of a rdfs:subPropertyOf axiom.
> I therefore propose that we CLOSE ISSUE-83 without doing anything  
> on the
> twin grounds that it both compromises decidability in OWL 1.1 and  
> is not
> handled by tools, and that there is nothing special that needs to be
> done in OWL Full.
> Peter F. Patel-Schneider
> Bell Labs Research
> PS:  If the "undecidability" was not present above then it would be
>      reasonable to POSTPONE the issue.  However, undecidability
>      conflicts with the goals of OWL DL (and OWL 1.1) and thus I
>      strongly believe that CLOSURE is much more appropriate.
Received on Thursday, 13 December 2007 18:00:55 UTC

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