t this original
<code>var</code> may be garbage collected if it is not referred from other data,
giving unpredictable results. See also <code><a
href="refB.html#byte">byte</a></code>.

<pre>
: (setq X (box 7))
-> $370237372176
: (adr X)
-> 533244889064
: (adr @)
-> $370237372176
: (val @)
-> 7
: (struct (adr X) 'N)
-> 114
$: (struct (adr X) T)
-> 7
</pre></dd>

<dt><a id="*Allow"><code>*Allow</code></a></dt>
<dd>A global variable holding allowed access patterns. If its value is
non-<code>NIL</code>, it shou