<dd>Aborts the execution of <code>prg</code> if it takes longer than
<code>cnt</code> seconds, and returns <code>NIL</code>. Otherwise, the result of
<code>prg</code> is returned. <code><a href="refA.html#alarm">alarm</a></code>
is used internally, so care must be taken not to interfer with other calls to
<code>alarm</code>.

<pre>
: (abort 20 (in Sock (rd)))  # Wait maximally 20 seconds for socket data
</pre></dd>

<dt><a id="abs"><code>(abs 'num) -> num</code></a></dt>
<dd>Returns the absolute value of th