ll parameters after <code class="mendoza-code">&amp;opt</code> are <code class="mendoza-code">nil</code> if not supplied.
</p>
<pre class="mendoza-codeblock"><code data-language="janet">(<span class="mdzsyn-coresym">defn</span> <span class="mdzsyn-symbol">my-opt-function</span>
 <span class="mdzsyn-string">"A dumb function with optional arguments."</span>
 [<span class="mdzsyn-symbol">a</span> <span class="mdzsyn-symbol">b</span> <span class="mdzsyn-symbol">c</span> <span class="mdzsyn-symbol">&amp;opt</spa