title: What does the parameter in the second lambda do?
body: <p>This is from SICP Video Lectures, Lecture 2a around the 39:51 mark.</p>
  
  <pre><code>(DEFINE (SQRT X)
     (FIXED-POINT
        (AVERAGE-DAMP (LAMBDA Y (/ X Y)))
        1)) 
  
  (DEFINE AVERAGE-DAMP
     (LAMBDA f
        (LAMBDA x (AVERAGE (f x) x))))
  </code></pre>
  
  <p>What does the <code>x</code> in the second lambda do in AVERAGE-DAMP and how is it being accessed? I don't understand what exactly is being passed to it. </p>