anchor.diff:       (error "Debe ingresar la cantidad de ejércitos adicionales del territorio")
        ir)
      (owner nil a)
  -   (armies nil a)))
  +   (armies nil a)
  +   (movable-armies nil a)))
   
   (defclass* game-map ()
     ((territories (error "Debe especificar los territorios") ir)
  
positive.code:        (setf (owner (territory game territory)) (player game player))
         (setf (armies (territory game territory)) 1)))))
  
  (defgeneric move-armies (game from to amount)
    (:method ((game game) origin-key destination-key amount)
     (let ((origin (territory game origin-key))
  
negative.code:        (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"))
       (decf (armies origin) amount)
       (decf (movable-armies origin) amount)
       (incf (armies destination) amount))))
  
  (defgeneric place-armies (game where amount)
  