"Sum three numbers."</span>
 [<span class="mdzsyn-symbol">x</span> <span class="mdzsyn-symbol">y</span> <span class="mdzsyn-symbol">z</span>]
 (<span class="mdzsyn-coresym">+</span> <span class="mdzsyn-symbol">x</span> <span class="mdzsyn-symbol">y</span> <span class="mdzsyn-symbol">z</span>))

(<span class="mdzsyn-coresym">defn</span> <span class="mdzsyn-symbol">api-fun</span>
 <span class="mdzsyn-string">"Do a thing."</span>
 [<span class="mdzsyn-symbol">stuff</span>]
 (<span class="mdzsyn-coresym">+</spa