Indirect imports (XML Spy versus XERCES)

Hi all,

Suppose the following example:

schema importininclude.xsd
<xs:schema ... targetnamespace="A">
  <xs:element name="A"/>

schema include.xsd
<xs:schema targetnamespace="B">
  <xs:import namespace="A" schemaLocation="importininclude.xsd"/>


schema main.xsd
<xs:schema targetnamespace="B" xmlns:px="A">
  <xs:include schemaLocation="include.xsd"/>
  <xs:element ref="px:A"/>

XML Spy is able to handle such an "indirect" import, they use an
"xs:include" quasi as a text replacement and I think that is OK.

XERCES needs the xs:import in main.xsd in order to know "px:A".


Does anybody know a W3C rule for that??


Thanks in advance


David