title: LISP - Closest function without setq/setf etc
body: <p>I'm trying to write the "closest" function,in Lisp, without using setq/setf etc...</p>
  
  <p>The function finds the nearest vector of a given vector (finding it on a list of lists).</p>
  
  <p>I tried but without sets is too hard,thanks a lot.</p>