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

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 13 Dec 2007 10:05:13 -0500 (EST)
Message-Id: <20071213.100513.249973442.pfps@research.bell-labs.com>
To: public-owl-wg@w3.org

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 15:24:47 GMT

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