anchor.diff:  (defmethod initialize-instance ((game game) &key game-map players)
     (with-slots ((the-game-map game-map)
                  (the-players players)
  -               (the-head-player head-player)
  +               (the-players-round players-round)
                  (the-turn-player turn-player)) game
       (setf the-game-map
             (typecase game-map
  
positive.code:             (t (read-map game-map))))
      (setf the-players (make-hash-table :test 'equalp))
      (dolist (name players) (add-player game name))  
      (setf the-head-player (copy-list players))
      (setf the-turn-player (copy-list players))))
  
  (defgeneric territory (container key)
    (:method ((container game-map) key)
  
negative.code:    (territory (game-map container) key)))
  
  (defgeneric head-player (game)
    (:method ((game game)) (car (slot-value game 'players-round))))
  
  (defgeneric turn-player (game)
    (:method ((game game)) (car (slot-value game 'turn-player))))
  
  (defgeneric pass-head (game)
    (:method ((game game))
     (pop (slot-value game 'players-round))
     (head-player game)))
  
  (defgeneric pass-turn (game)
    (:method ((game game))
     (with-slots ((the-turn-player turn-player)
                  (the-players-round players-round)) game
       (pop the-turn-player)
       (when (eq the-turn-player the-players-round)
         (pass-head game)
         (pop the-turn-player)))
     (turn-player game)))
  
  (defmethod territories ((game game))
  