title: Cannot do sum in lisp with do loop
body: <pre><code>(defun suma (L)
    (setq var 0)
    (do 
        ((i 0 (+ i 1)))
        ((= i (length L)))
      (+ var (nth i L)))
    var)
  </code></pre>
  
  <p>Why does it always returns 0?</p>
  
  <p>Shouldn't it return sum of list L?</p>