d both ways. This occurs when a mixture
        of signed/unsigned types are involved and indicates that in both directions
        there are values which can fall out of range.
      </p>
<p>
        Given the range relation (subranged or not) of a conversion direction <code class="computeroutput"><span class="identifier">S</span><span class="special">-&gt;</span><span class="identifier">T</span></code>, it is possible to classify <code class="computeroutput"><span class="identifier">S</span></code> and <c