Re: OWL working drafts - feedback

From: "Emery, Pat" <pemery@grci.com>
Subject: RE: OWL working drafts - feedback
Date: Mon, 9 Sep 2002 10:42:58 -0400 

> I can see and agree with the rationale of allowing me to specify properties
> with no values.  My uneasiness should have been better expressed as, "Why
> the positive-integer restriction of minCardinality?".

Hmm.  This may be a bit of a bug.

minCardinality(0) is a null restriction - it has no effect.

> Maybe what is missing is more description of the rational on the cardinality
> definitions in the document both under OWL and OWL-LITE.

This could be.  It is most probably an issue for either the Feature
Synopsis or the Reference document.

> 5.1.2 does not seem to allow for minCardinality 0 | maxCardinality 0 |
> minCardinality 1 maxCadinality 0.  If this is correct I think it should be
> spelled out in the text of the abstract Syntax document as well as some of
> the other documents that seem to specify only that the cardinality
> descriptors are restricted to 0 or 1.

> 5.3.3/5.2.3 allows cardinality 0 under cardinality as a non-negative-integer
> but not minCardinality 0 under minCardinality as a positive-integer. If
> cardinality 0 is expanded out to minCardinality 0 maxCardinality 0.  This
> seems to imply minCardinality can have a value of 0 but only if
> maxCardinality is also 0.  Again this is ok but should definetly be spelled
> out if this is correct.

In conjunction with this explicit allowance of minCardinality(0), the
restriction to positive integer is certainly a bug.  I'll change it.

> Also of slight note is that the http://www.w3.org/2002/07/owl document has
> all the cardinalities listed as non-negative integers.

Thanks for picking up this divergence between the various documents.
> 
> 
> Pat

peter