;l1&nbsp;l2</code> will return a
    sorted list containing all the elements of <code class="code">l1</code> and <code class="code">l2</code>.
    If several elements compare equal, the elements of <code class="code">l1</code> will be
    before the elements of <code class="code">l2</code>.
    Not tail-recursive (sum of the lengths of the arguments).</p>
</div>
</div>
<h7 id="6_Iterators">Iterators</h7>
<pre><span id="VALto_seq"><span class="keyword">val</span> to_seq</span> : <code class="type">'a list -&