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Re: key/keyref problem

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 23 Aug 2001 10:28:58 +0100
To: <priscilla@walmsley.com>
Cc: <kboo@ca.ibm.com>, "'Jun Wang'" <t-junw@microsoft.com>, "'Aung Aung'" <aaung@microsoft.com>, <xmlschema-dev@w3.org>
Message-ID: <f5bu1yzktut.fsf@cogsci.ed.ac.uk>
"Priscilla Walmsley" <priscilla@walmsley.com> writes:

> Right, I see.  I assumed that the example was intended to show a and b as
> siblings.  But since no type is specified for the element "b", it is
> unconstrained - it can contain any elements and have any attributes.  This
> means that it might contain "a", in which case it would be valid.

All in agreement now.

In summary:  the point to bear in mind is that validation occurs with
respect to each instance of the _scoping_ element for a key, keyref or 
unique constraint.  Whatever is available at that point == is within
the scope of that element is liable to collision checking (key/unique) 
and available for reference (keyref).

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Thursday, 23 August 2001 05:28:41 GMT

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