an>&#45;&gt;</span> <span class="type-var">'a</span> <span>&#45;&gt;</span> bool)</span></span> <span>&#45;&gt;</span> bool</code></dt><dd><p><code>mem t x ~equal</code> is true if there's an element <code>y</code> in <code>t</code> such that <code>equal
      x t</code> is <code>true</code></p></dd></dl><dl><dt class="spec value" id="val-max"><a href="#val-max" class="anchor"></a><code><span class="keyword">val</span> max : <span>compare:<span>(<span class="type-var">'a</span> <span>&#45;&gt;</span> <span 