- From: Jeremy Carroll <jeremy@topquadrant.com>
- Date: Fri, 15 Oct 2010 09:41:07 -0700
- To: Antoine Zimmermann <antoine.zimmermann@deri.org>
- CC: Toby Inkster <tai@g5n.co.uk>, Jesse Weaver <weavej3@rpi.edu>, semantic-web@w3.org
> Jeremy, > > > >> === >> >> The crucial part of >> http://www.w3.org/TR/2009/REC-owl2-direct-semantics-20091027/#Interpretations >> >> >> is the phrase: >> "disjoint with /Δ_I / " >> >> my assertion is that this phrase is not externally visible - I haven't >> checked that. >> >> I wonder if this was an unnecessary addition. i.e. that all interesting >> theorems about OWL follow even if that part of the defn is omitted. > > This is a strict necessity in the DL-based semantics. Perhaps it > would be possible to devise a description logic where datatypes and > classes can overlap but as far as I know, it's been very little > studied (maybe for some good reason which I don't know). Oh. Can you give an example of a false consequence of the system without the phrase, but otherwise identical to OWL 2 DL. I thought it was only necessary because the primary literature had always made this assumption and no one particularly felt like challenging it. It would be a silly risk to remove a phrase as probably superfluous ... If it is known to be necessary that is a different situation. Jeremy
Received on Friday, 15 October 2010 16:41:36 UTC