lue">value</a></code></dt><dt class="spec value" id="val-find_opt"><a href="#val-find_opt" class="anchor"></a><code><span class="keyword">val</span> find_opt : <a href="index.html#type-key">key</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <span><a href="index.html#type-value">value</a> option</span></code></dt><dt class="spec value" id="val-find_first"><a href="#val-find_first" class="anchor"></a><code><span class="keyword">val</span> find_first : <span>(<a href="index