complexType derivation issue

Dear all,

I'm not very clear with a derivation constraint in the document
   XML Schema Part 1: Structures   W3C Working Draft 7 April 2000

You can find in 5.11 Complex Type Definition Constraints :
    ..
    Constraint on Schemas: Derivation Valid (Extension)
            If the {derivation method} is extension:
            1.1
                If the {base type definition} is a complex type
definition:
                ...
                1.1.4  The {content type} of the complex type itself
must not be a simple type definition;
    ...

Does it mean that the following schema is not valid:

    <complexType name="t1" base="integer" derivedBy="extension">
        <attribute name="a1" base="integer"/>
    </complexType>
    <complexType name="t2" base="t1" derivedBy="extension">
        <attribute name="a2" base="integer"/>
    </complexType>

And if it is true, I don't really see why.

Thank you for your response,

Cedric Thienot.

Received on Friday, 25 August 2000 09:59:23 UTC