question about substitutionGroup tests

test typeDef00204m has the following schema:

<xsd:schema
  xmlns="ElemDecl/typeDef"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="ElemDecl/typeDef">

  <xsd:element name="Head" type="xsd:boolean"/>

  <xsd:element name="root" substitutionGroup="Head"/>

</xsd:schema>

according to the meta data this schema is valid, however I stumble about
point 4 of Schema Component Constraint: Element Declaration Properties 
Correct.

It says: the {type definition} of the element declaration must be validly 
derived from the {type definition} of the {substitution group affiliation}

So the type of 'root' element must be validly derived from the type of 'Head'.
But I can't see how xsd:AnyType (the default type for element) can be derived 
from xsd:boolean...

Ciao,
Tobias

Received on Wednesday, 12 November 2008 15:52:55 UTC