nd Sussman later observed that in their interpreter the code
for dealing with actors was identical to that for functions and thus
there was no need to include both in the language.</p>
<p>
</p>
</blockquote>
<p>
A <em>tail call</em><a name="%_idx_80"></a> is a procedure call that occurs
in a <em>tail context</em>.  Tail contexts are defined inductively.  Note
that a tail context is always determined with respect to a particular lambda
expression.</p>
<p>
</p>
<ul>
<li>
<p>The last expression within the body