 class="anchored"><a href="#val-remove_by_rank" class="anchor"></a><code><span><span class="keyword">val</span> remove_by_rank : <span><a href="#type-rank">rank</a> <span class="arrow">&#45;&gt;</span></span> <span><a href="#type-t">t</a> <span class="arrow">&#45;&gt;</span></span> <a href="#type-t">t</a></span></code></div></div><div class="odoc-spec"><div class="spec value" id="val-mem" class="anchored"><a href="#val-mem" class="anchor"></a><code><span><span class="keyword">val</span> mem : <span><a href=