xs:choice question...

[Brian J Gentry <Brian.j.Gentry@tntlogistics.com>]

Hello,
         I
have a schema that needs to require 1 of 2 elements, but also allow for
both of them. So if the elements are A & B, then A alone is valid,
B alone is valid, A & B are valid, but ~A & ~B is invalid.

I tried the following..

             
          <xs:choice>
             
           <xs:sequence>
             
               
          <xs:element
name="A"
minOccurs="1"/>
             
               
          <xs:element
name="B"
minOccurs="0"/>
             
           </xs:sequence>
             
           <xs:sequence>
             
               
          <xs:element
name="A"
minOccurs="0"/>
             
               
          <xs:element
name="B"
minOccurs="1"/>
             
           </xs:sequence>
             
          </xs:choice>

But this is not working as it makes
the model non-deterministic.  Is there a way to solve this?

Thanks for your time and kind regards,
Brian Gentry