I'm not sure that buys you anything, since the base element, Condition, can be used as a placeholder for any extension of Condition
via xsi:type or element substitution. I believe it would still be legal for me to just add as many extra copies as I wanted.
What you're after would require normative language ruling out multiple appearances of the condition, but as long as it's clear that
>1 is no different than 1, I'm not sure it's worth doing. It seems more complex to have to toss out such an assertion than to just
ignore the extras.
-- Scott
