Michael Kay wrote:

> and there's no statement anywhere about what it means precisely for a
> component to be "from" a particular schema document. Saxon's interpreta=
tion
> is that a model group definition component comes "from" a schema docume=
nt if
> the defining xs:group element is contained in that schema document, and=
 an
> xs:group element in an included document therefore does not qualify.
> However, one could legitimately argue that the specification of xs:incl=
ude
> states:
> 
> "The .XML Schema. corresponding to <schema> contains not only the compo=
nents
> corresponding to its definition and declaration [children], but also al=
l the
> components of all the .XML Schemas. corresponding to any <include>d sch=
ema
> documents."

Thanks for clarification, now I see. It seems that both interpretations
(ie. taking includes into account and ignoring them) can be considered
as a correct according to the specification.

However I would argue that approach which takes also included schemas
into account is much more useful for schema developers. In this case you
doesn't have to study details of how schema is composed from separate
files, you just use it as a single piece. Without this approach my
example have to duplicate dozen of schema files in order to redefine
just single group, because this group is defined at the second level of
inclusion.

> I personally think xs:redefine is one of those facilities (xsi:nil is
> another) where you're better off pretending it doesn't exist. Implement=
ors
> don't have that luxury, but users do.

OK, it was just example for forthcoming XML schemas training anyway.

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