Re: Quick technical question.

"Henry S. Thompson" wrote:

> Michael Anderson <michael@research.canon.com.au> writes:
>
> > Hi all,
> > Does someone understand clause 1.6 of
> > http://www.w3.org/TR/xmlschema-1/#rcase-NameAndTypeOK ?
> >
> > "R's { type definition } is validly derived given {extension } from B's
> > {type definition} as defined by Type Derivation OK (Complex)(5.11) or
> > Type Derivation OK(Simple)(5.12) as appropriate".
>
> This means that the derivation can't involve {extension} -- it's as if
> B had had block='extension'.  The point is that to derive by
> restriction, the type derivation path can't involve extension.

Thanks for the reply.

Unfortunately i admit I'm still confused.  Having B's block='extension' just
means that substitute groups of B can't have an extended type of B.  This has no
bearing on its relationship with R.  R and B are both the Element Declarations
already obtained after checking that they were validly substituted for (say) Q
and A respectively.
What is the link from B to R with the block attribute?

thanks again,
mick.