ay that (A) expressions in domains
            that share a common super-domain are interoperable, and (B) expressions that are in
            the default domain (or a sub-domain thereof) are interoperable with <span class="emphasis"><em>all</em></span>
            expressions. The rules are as follows:
            </p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
                A sub-domain is <span class="emphasis"><em>stronger</em></span> than its super-domain.
 