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Re: Classifying with Inequalities

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Mon, 10 May 2004 18:33:06 +0100
Message-ID: <409FBCD2.9020009@hplb.hpl.hp.com>
To: Bob MacGregor <macgregor@ISI.EDU>
Cc: www-rdf-logic@w3.org

Bob MacGregor wrote:

> We do a lot of reasoning with inequalities, e.g., restricting
> events within certain dates, or logging observations
> within rectangular regions. It would be extremely
> useful to be able to define classes that include such
> restrictions and to arrange them in a classification hierarchy.
> My impression is that there
> is no inequality operator for any of the OWL variants.  My
> question is, are inequalities compatible with OWL, or is this
> yet another area (e.g., like metadata and property composition) 
> where the existing OWL infrastructure falls far short of user needs?
> 
> In either case, it would be very nice if there were inequality properties
> for greater than, less than, greater-than-or-equal, less-than-or-equal
> blessed by a W3C standard. Is there any possibility of this
> happening in the near future?
> 
> Note:  Loom added the ability to classify scalar
> intervals, and restrictions that reference them, very early on.  
> Thus, the notion of the kind of classification I need has been
> around for a very long time.
> 
> Cheers, Bob
> 
> 
> 

Bob

simple inequalities will be addressable if the SWBPD/XML Schema TF gets 
off the ground and solves one of the two problems currently in its scope.

The latest draft of the TF description is:

http://lists.w3.org/Archives/Public/public-swbp-wg/2004Apr/0199

The problem which would address simple inequalities is URIs for user 
defined XS datatypes. This allow the specification of intervals over 
numbers and dates, patterns etc. (See XML Schema (Part 2)).
What this does not give is a general inequality. Thus you cannot define 
an inequality between two different attributes, merely a fixed range for 
one of them.

I am mildly optimistic that this TF will start and will manage to make 
progress. We have not yet begun discussing how any results will be 
delivered other than as a non-normative WG Note.

Jeremy
Received on Monday, 10 May 2004 13:34:02 UTC

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