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Re: ISSUE 5.2 Language Compliance Levels - proposed clarification

From: Deborah McGuinness <dlm@ksl.Stanford.EDU>
Date: Wed, 29 Jan 2003 18:58:38 -0800
Message-ID: <3E3894DE.8A1DA0A@ksl.stanford.edu>
To: Jim Hendler <hendler@cs.umd.edu>
CC: Ian Horrocks <horrocks@cs.man.ac.uk>, Jeremy Carroll <jjc@hpl.hp.com>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, www-webont-wg@w3.org

let me add a little clarification hopefully:

Jim Hendler wrote:

> >>
> >>  If I have understood correctly, without the complete class descriptions the
> >>  subscriptions could not be made. For instances if I want messages both about
> >>  HP and the SemanticWeb, I can say that the messages I want are subClassOf
> >>  both of these, but without the complete part of the class description any
> >>  particular message that has been categorized as in both, may fail to be in
> >>  my subset of the intersection.
> >
> >Correct.

just to add a little expansion - given a lack of complete class descriptions
(sometimes also referred to as lacking sufficiency conditions and sometimes referred
to as lacking "iff" semantics)
and given:

HPSemWebMessages  described by:  (and HPMessages SemWebMessages)
HPSemWebDLMessages  described by:  (and HPMessages SemWebMessages DLMessages)

without complete classes, a reasoner would fail to deduce that HPSemWebDLMessages is
a subclass of HPSemWebMessages.  (in order to do this, the reasoner would need the
sufficiency portion of the description or the iff portion of the description.)
Also, a particular message that is stated individually to be an instance of
HPSemWebMessages and
ALSO stated to be an instance of DLMessages, will NOT be recognized to be an
instance of
HPSemWebDLMessages.   (again the reasoner would need the sufficiency portion of the
description to do the recognition).

However any message that is stated to be an instance of HPSemWebDLMessages would
inherit that it is an instance of HPMessages and SemWebMessages and DLMessages.
(this uses the necessary portion of the description or the if portion of the
Similarly any new message class that is described as a subclass of
HPSemWebDLMessages will also be a subclass of HPMessages, SemWebMessages, and
DLMessages (again by inheritance).

> >
> >> --
> Professor James Hendler                           hendler@cs.umd.edu
> Director, Semantic Web and Agent Technologies     301-405-2696
> Maryland Information and Network Dynamics Lab.    301-405-6707 (Fax)
> Univ of Maryland, College Park, MD 20742          240-731-3822 (Cell)
> http://www.cs.umd.edu/users/hendler

 Deborah L. McGuinness
 Knowledge Systems Laboratory
 Gates Computer Science Building, 2A Room 241
 Stanford University, Stanford, CA 94305-9020
 email: dlm@ksl.stanford.edu
 URL: http://ksl.stanford.edu/people/dlm/index.html
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801 705 0941
Received on Wednesday, 29 January 2003 21:55:51 UTC

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