RE: not a complete functional mapping - help

I believe your example is valid per the spirit of the spec, but not the letter of the spec, 
which is what Xerces enforces.  XSV reports the schema as valid (after filling in MODULType).

This a case that is covered by the note in the relevant section of the spec:

    Note: This clause is in principle more restrictive than absolutely necessary,
    but in practice will cover all the likely cases, and is much easier to specify
    than the fully general version.

I tried a few variations of your schema without any luck. Wrapping the choice in a 
sequence seemed promising, but XML Schema doesn't even allow 

    <xsd:sequence maxOccurs="unbounded">
      <xsd:element ref="A"/>
    </xsd:sequence>

to be restricted by:

     <xsd:sequence>
      <xsd:element ref="A"/>
      <xsd:element ref="A"/>
    </xsd:sequence>

xan