eywordsign">'</span>a)&nbsp;list&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="keywordsign">'</span>a&nbsp;t<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">end</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">type</span>&nbsp;constr&nbsp;=&nbsp;(<span class="constructor">OpamFormula</span>.relop&nbsp;*&nbsp;t)&nbsp;<span class="constructor">OpamFormula</span>.formula<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;c