((let ((arr (new-array 3 0))) (let ((res (:increment arr 0))) (print res)))
 (:increment (arr pos)
  (let ((len (alen arr)))
   (let ((bool (< pos len)))
    (if bool
     (let ((val (aref arr pos)))
      (let ((nval (+ 1 val)))
       (let ((x (aset arr pos nval)))
        (let ((npos (+ pos 1)))
         (:increment arr npos)))))
     arr)))))
