anchor.diff:  
   (defclass* game ()
     ((game-map nil r)
  -   (fsm nil)
  +   (fsm nil r)
      (players (make-hash-table :test 'equalp) r)
  -   (players-round nil)
  +   (players-round nil a)
      (turn-player nil)
  -   (pending-armies nil r)))
  +   (pending-armies nil a)))
   
   (defmethod initialize-instance :after ((game game) &rest rest
                                                      &key game-map players)
  
positive.code:        (error "Los territorios deben estar conectados"))
       (unless (eq (owner origin) (owner destination))
         (error "Los territorios tienen que tener el mismo dueño"))
       (unless (> amount 0)
         (error "No se pueden mover 0 o menos ejércitos"))
       (unless (>= (movable-armies origin) amount)
         (error "No hay suficientes ejércitos"))
  
negative.code: 
  (defgeneric head-player (game)
    (:method ((game game))
     (car (players-round game))))
  
  (defgeneric turn-player (game)
    (:method ((game game))
  