title: Recursive Addition in Lisp
body: <p>I'm a beginner and I am trying to teach myself Common Lisp and during my self-study I have written a function that I believe should work for recursive addition of two arguments. However, the function always fails. Why is that?</p>
  
  <pre><code>(defun sum (n m)
    ;;;Returns the sum of n and m using recursion
    (cond ((eq m 0) n))
    (sum (1+ n) (1- m)))
  </code></pre>
  
  <p>As I understand it, it should continually add 1 to n while decrementing m until m is 0 at which point, the recursive addition is complete</p>