Re: derivation in XML Schema

Jeni Tennison <jeni@jenitennison.com> writes:

<snip/>

> > Do you know the reason why the same kind of inheritance doesn't
> > apply to the prohibition of derivation itself? If B says it is final
> > with respect to restriction, and E extends B, there is no
> > prohibition on R restricting E. So if the designer of B thinks he is
> > preventing derivation by extension, she must still be careful to
> > forbid substitution by extensions which may still be produced by
> > inserting a restriction in between.
> 
> Hmm... I can't think of anything. Possibly someone in the XML Schema
> WG would be able to give us a clue?

No good reason -- I think we didn't think about that case very hard,
if at all.  Arguably this is a loophole that should be closed in 1.1.

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2002, 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/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]