(let ((a 16)
      (b a))
  (+ b a))
19
</pre> In other words, <code class="scheme"><span class="variable">b</span></code>'s reference to <code class="scheme"><span class="variable">a</span></code> is bound to the top-level <code class="scheme"><span class="variable">a</span></code>, rather than the inner one. <p><a href="index.htm">Intermediate Student with Lambda Language</a></p></body></html>