5;&gt;</span> <span class="type-var">'c</span>)</span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> option</span> <span>&#45;&gt;</span> <span><span class="type-var">'b</span> option</span> <span>&#45;&gt;</span> <span><span class="type-var">'c</span> option</span></code></dt><dd><p>meet on options</p></dd></dl><dl><dt class="spec value" id="val-merge_bot"><a href="#val-merge_bot" class="anchor"></a><code><span class="keyword">val</span> merge_bot : <span><span class="type-var">'a</span> op