is done, and <code>NIL</code>
is returned immediately.

<pre>
: (do 11 (prin ".") (at (0 . 3) (prin "!")))
...!...!...!..-> NIL
</pre></dd>

<dt><a id="atom"><code>(atom 'any) -> flg</code></a></dt>
<dd>Returns <code>T</code> when the argument <code>any</code> is an atom (a
number or a symbol). See also <code><a href="refN.html#num?">num?</a></code>,
<code><a href="refS.html#sym?">sym?</a></code> and <code><a
href="refP.html#pair">pair</a></code>.

<pre>
: (atom 123)
-> T
: (atom 'a)
-> T
: (atom NIL)
-> T
