e <code class="code"><span class="constructor">Invalid_argument</span>&nbsp;<span class="string">"List.nth"</span></code> if <code class="code">n</code> is negative.</p>
</div>
</div>

<pre><span id="VALnth_opt"><span class="keyword">val</span> nth_opt</span> : <code class="type">'a list -&gt; int -&gt; 'a option</code></pre><div class="info ">
<div class="info-desc">
<p>Return the <code class="code">n</code>-th element of the given list.
    The first element (head of the list) is at position 0.
    Return