Confused about Primer Example section 4.7 vs Structures Constraint on Complex Types Sec 5.11 Extension particularly 1.1.4.1

My reading of Structures "Constraints on Complex Types",
Section 5.11 http://www.w3.org/TR/2000/CR-xmlschema-1-20001024/#coss-ct
Derivation Valid (Extension)
clause 1.1.4 and particularly clause 1.1.4.1 makes me think that
the Primer Example in "Abstract Elements and Types" section  4.7
http://www.w3.org/TR/2000/CR-xmlschema-0-20001024/#abstract
has a definition for complexType "car" which is not allowed.

Is this a problem of me being unable to see the parsing of all the
"ands" and "ors" which are in clause 1.1.4 of
Derivation Valid (Extension) paragraphs of Section 5.11 of Structures?

Primer example:

<complexType name="Vehicle" abstract="true"/>

<complexType name="Car">
         <complexContent>
                 <extension base="target:Vehicle"/>
          </complexContent>
</complexType>


Structures: clause 1.1.4 of  Derivation Valid (Extension) paragraphs in
section 5.11:

   Either the {content type} of the {base type definition} and the {content
type} of the complex
   type definition itself must be the same simple type definition, or else
the {content type} of
   the complex type definition itself must specify a particle and either
the {content type} of the
   {base type definition} must be empty or
       1.1.4.1  both {content type}s must be mixed or both must be
element-only;

Thanks,
Bob

Bob Schloss
IBM Thomas J. Watson Research Center
Hawthorne, New York, USA

Received on Wednesday, 8 November 2000 15:37:17 UTC