schema extension question

Hi-

 

Hi-

 

My group is designing a schema for neuroimaging.  We're having trouble
tackling what seems like a basic problem.  We'd like to create
containers that have similar content, along these lines:

 

<StudyType1>

            <StudyType1_part1>Some complex content<StudyType1_part1>

            <StudyType1_part2>Different complex
content<StudyType1_part2>

</StudyType1>

<StudyType2>

            <StudyType2_part1> Some complex content <StudyType2_part1>

            <StudyType2_part2> Different complex content
<StudyType2_part2>

</StudyType1>

 

*_part1 derive from the same base type (abstract_part1) and *_part2
derive from a different base type (abstract_part2).  Additionally, we
want to enforce that for each study type, part1 and part2 are matched by
study type (i.e. StudyType1 includes only StudyType1_part* elements).

 

Is there an appropriate XML Schema representation for this?  We've tried
substitution, extension, restriction... Nothing seems to capture this
sort of content.  Any advice would be appreciated.

 

Regards, 

Dan Marcus