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RE: syntax task force - differences between the two approaches

From: Ian Horrocks <horrocks@cs.man.ac.uk>
Date: Thu, 27 Feb 2003 17:04:11 +0000
Message-ID: <15966.17675.394060.826616@merlin.horrocks.net>
To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
Cc: "Sean Bechhofer" <seanb@cs.man.ac.uk>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, <www-webont-wg@w3.org>

On February 27, Jeremy Carroll writes:
> 
> > The alternative presentation, particularly the approach to equivalence
> > and disjointness is, to me, less clear.
> 
> The earlier complexities have gone from the version:
> 
> http://sealpc09.cnuce.cnr.it/jeremy/owl-syntax/2003-21-Feb/dl-syntax.html
> 
> Peter had indicated that he saw semantic difficulties with my earlier
> proposal, and I saw that he was right.
> 
> The difference on equivalent classes and disjointness is now simply how to
> treat n>2 in such statements, which I don't think is unsuromountable.

This kind of thing *is* important when it comes to building
tools. E.g., OilEd allows users to assert that a set of classes are
disjoint - something that is a pretty common requirement. If saving
the file as RDF means decomposing such statements into pairwise
disjointness axioms, then when the RDF is read back in it is
impossible to know which if any of these should be re-grouped. 

For users, the result is that every time they go through a
save-restore cycle they find all their disjointness axioms
have fragmented. This can be both irritating and confusing.

I don't think that we give/have given anything like enough
consideration to these sorts of practical/implementation
considerations in our design.

Ian
Received on Thursday, 27 February 2003 12:05:21 GMT

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