t-in classes. This presented some problems for Gray streams,
because ABCL CLOS can't use a built-in class as a base class, and Gray streams derive from
a system-stream class. This was corrected by converting ABCL streams to be structure-objects
instead of built-in classes, allowing CLOS to derive from the streams. There was, however, another
problem that revealed a need to change the design in more drastic ways.</p>
<div class="section" id="the-problem-with-the-previous-design">
<h2>The problem with the pre