Yes, it's valid. It would be valid even if you 
changed the third particle to
 
<xsd:element name="b" form="unqualified" 
type="xsd:int"/>
 
because although the two "b" elements now have different 
types, they also have different names - one is qualified and the other 
isn't.
 
The clause that I think you are worried about 
is:
 
Schema Component 
Constraint: Element Declarations Consistent

If the {particles} contains, 
either directly, indirectly (that is, within the {particles} of a 
contained model group, recursively) or &middot;implicitly&middot; two or more element 
declaration particles with the same {name} and {target 
namespace}, then all their type definitions must be the same top-level 
definition, 
 
and in this case, your two element declaration particles 
have a different {target namespace}, so the rule doesn't 
apply.
 
If you change the content model to
 
                     
<xsd:sequence><o:p></o:p>
                                
<xsd:element name="b"/><o:p></o:p>
                                
<xsd:element name="c"/><o:p></o:p>
                                
<xsd:element name="b"/><o:p></o:p>
                        
</xsd:sequence><o:p></o:p>
 
Then it's still valid because the two "b" elements both 
have the same type. (It's not 100% clear that xs:anyType is a "top-level" 
type definition - the term "top-level" doesn't seem to be defined anywhere - but 
the rule as quoted above is followed by further explanation which makes it 
clear). 
 
Michael Kay
http://www.saxonica.com/


  
  
  From: Shlomo Yona [mailto:S.Yona@F...] 
  
Sent: 29 May 2007 14:13
To: 
  xml-dev@l...
Subject: [xml-dev] Elements declaration with 
  same name in same complexType and name qualification


  
  
  Hello,<o:p></o:p>
  <o:p> </o:p>
  Is the following 
  considered valid or not?<o:p></o:p>
  <o:p> </o:p>
  Schema:<o:p></o:p>
  <o:p> </o:p>
  <?xml version="1.0" 
  encoding="UTF-8"?><o:p></o:p>
  <xsd:schema 
  xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" 
  targetNamespace="foo" xmlns="foo"><o:p></o:p>
          
  <xsd:element name="a"><o:p></o:p>
                  
  <xsd:complexType><o:p></o:p>
                          
  <xsd:sequence><o:p></o:p>
                                  
  <xsd:element name="b"/><o:p></o:p>
                                  
  <xsd:element name="c"/><o:p></o:p>
                                  
  <xsd:element name="b" form="unqualified"/><o:p></o:p>
                          
  </xsd:sequence><o:p></o:p>
                  
  </xsd:complexType><o:p></o:p>
          
  </xsd:element><o:p></o:p>
  </xsd:schema><o:p></o:p>
  <o:p> </o:p>
  <o:p> </o:p>
  Instance:<o:p></o:p>
  <o:p> </o:p>
  <bar:a 
  xmlns:bar="foo"><o:p></o:p>
        
  <bar:b/><o:p></o:p>
        
  <bar:c/><o:p></o:p>
        
  <b/><o:p></o:p>
  </bar:a><o:p></o:p>
  <o:p> </o:p>
  I think it should be 
  valid because the two local declarations of the element b have the same data 
  type, anyType, in this case. I could not feel confident with my understanding, 
  though, as I did not read that this is OK in the 
  standard.<o:p></o:p>
  <o:p> </o:p>
  Thanks.<o:p></o:p>
  <o:p> </o:p>
  Shlomo.<o:p></o:p>