s="mdzsyn-coresym">fn</span> [<span class="mdzsyn-symbol">x</span> <span class="mdzsyn-symbol">&amp;</span>] <span class="mdzsyn-symbol">x</span>) <span class="mdzsyn-number">1</span> <span class="mdzsyn-number">2</span>)</code></pre><p>The first expression creates an anonymous function that adds twice the first
argument to the second, and then calls that function with arguments 10 and 20.
This will return (10 + 10 + 20) = 40.
</p>
<p>There is a common macro <code class="mendoza-code">defn</code> that can b