nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;find&nbsp;:&nbsp;(elt&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;bool)&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;elt<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">end</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">module</span>&nbsp;<span class="constructor">Map</span>&nbsp;:<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<s