Re: Difficult logical relationship in complex type

  On 23/08/2010 17:39, McBride, David wrote:
>
> I'm having difficulties defining a logical relationship within a 
> complex type.  The complex type contains 4 sub-elements.  Let's call 
> them A, B, C, D.  The logical relationship is this:
>
> 1. One, or more of elements B, C, or D are required.
>
> 2. There may be zero or more instances of element A.
>
> 3. Element A may never be the only element.  In other words, there may 
> only be an instance of A, if there is also at least one instance of B, 
> C, or D.
>
> If I was just dealing with B, C, and D, I could handle that.  However, 
> adding the requirements for A has thrown me.
>
> Thanks for any responses, in advance.
>

Are there any ordering constraints?

If not, I would think this is stretching XSD 1.0 to the limits. It's 
obviously easy using XSD 1.1 assertions.

Michael Kay
Saxonica