anchor.diff:      (cond
         ((= x 1) (get-conf-keyboard))
         ((= x 2) (read-from-file (read)))
  -      (t return))))
  +      (t (do
  +           (format t "Please enter only 1 or 2.~%")
  +           (abort))))))
  
positive.code: (defun die ()
    (format t "The game configuration format is wrong.~%")
    (format t "Smaller discs go on top of the bigger ones.~%")
    (abort)) ; TODO: is this abort correct???
  
  ; ask the user for a filename
  (defun get-filename ()
  
negative.code: 
  ; the main move function. Moves from list a to b if possible
  (defun move-disc (a b)
    (if (and
          (not (null a))
          (< (first a) (first b)))
      (push (pop a) b)
      (format t "Your move was illegal. ~%"))
  
  ; TODO: can we set an alias to those (gethash :B stacks) things for easier access?
  ; function to start them all. main?
  