t><dt class="spec value" id="val-move_last_to_first"><a href="#val-move_last_to_first" class="anchor"></a><code><span class="keyword">val</span> move_last_to_first : <span><span class="type-var">'a</span> list</span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> list</span></code></dt><dt class="spec value" id="val-traverse_opt"><a href="#val-traverse_opt" class="anchor"></a><code><span class="keyword">val</span> traverse_opt : <span><span class="type-var">'a</span> list</span> <span>&#45;&g