e><span class="keyword">val</span> of_le : <span>le:<span>(<span class="type-var">'a</span> <span>&#45;&gt;</span> <span class="type-var">'a</span> <span>&#45;&gt;</span> bool)</span></span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> <a href="index.html#type-xcompare">xcompare</a></span></code></dt><dt class="spec value" id="val-of_opt"><a href="#val-of_opt" class="anchor"></a><code><span class="keyword">val</span> of_opt : <span>xcompare_elt:<span><span class="type-var">'a</span> <a href