anchor.diff:  ; our abort function in case of wrong game configuration
   (defun die ()
     (format t "The game configuration format is wrong.~%")
  -  (format t "Smaller discs go on top of the bigger ones.~%")
  +  (format t "Smaller discs go on top of the bigger ones. Aborting.~%")
     (abort))
   
   ; ask the user for a filename
   (defun get-filename ()
     (format t "Please type a file name... ")
  -  (read))
  +  (finish-output)
  +  (read-line))
   
   ; check if list is sorted
   (defun is-sorted (ls)
  
positive.code: (defun start ()
    (let ((x))
      (print-hello-msg)
      (setf x (read))
      (cond
        ((= x 1) (get-conf-keyboard))
        ((= x 2) (read-from-file (read)))
  
negative.code:   (dotimes (i 5)
      (format t "Disc: ~D - Please type the corresponding key that you want it placed.~%" (+ i 1))
      (let ((r))
        (setf r (read-line))
        (cond
          ((string-equal "a" r) (push i (gethash :A stacks)))
          ((string-equal "b" r) (push i (gethash :B stacks)))
  