">M</span> <span class="identifier">M</span> <span class="identifier">M</span> <span class="identifier">M</span> <span class="identifier">M</span>    
</pre>
<p>
        </p>
<p>
          While intersection on maps can be viewed as a <span class="emphasis"><em><span class="bold"><strong>generalisation
          of set intersection</strong></span></em></span>. The combination on Maps and
          Sets can be interpreted as a <span class="emphasis"><em><span class="bold"><strong>generalized
          select