eq" class="anchor"></a><code><span class="keyword">val</span> subseteq : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> bool</code></dt><dt class="spec value" id="val-contains"><a href="#val-contains" class="anchor"></a><code><span class="keyword">val</span> contains : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="B/index.html#type-t">B.t</a> <span>&#45;&gt;</span> bool</code></dt><dt class="spec value" id="val-contains_f