 a space-instances value is supplied, <var>instance</var> is
removed from all space instances and then added to the supplied space
instances.
</p>
<p><span class="fndoclabel">See also</span>
<br>&nbsp;&nbsp;&nbsp;&nbsp;<a href="ref-define-unit-class.html"><b>define-unit-class</b></a>
<br>&nbsp;&nbsp;&nbsp;&nbsp;<a href="ref-make-duplicate-instance-changing-class.html"><b>make-duplicate-instance-changing-class</b></a>
<br>&nbsp;&nbsp;&nbsp;&nbsp;<a href="ref-next-class-instance-number.html"><b>next-class-ins