n class="type-var">'a</span> list</span></code></dt><dt class="spec value" id="val-rev_append"><a href="#val-rev_append" class="anchor"></a><code><span class="keyword">val</span> rev_append : <span><span class="type-var">'a</span> list</span> <span>&#45;&gt;</span> <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-concat"><a href="#val-concat" class="anchor"></a><code><span class="keyword">va