>-&gt;</span>&nbsp;elt<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;choose&nbsp;:&nbsp;t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;elt<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;split&nbsp;:&nbsp;elt&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;t&nbsp;*&nbsp;bool&nbsp;*&nbsp;t<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs