anchor.diff:             :armies
              :player
              :read-map
  -           :move-armies))
  +           :move-armies
  +           :place-armies
  +           :attack))
   
   (in-package :ar.com.fchurca.frisk)
   
  
positive.code:   (decf (armies origin) amount)
    (incf (armies destination) amount))
  
  
negative.code:         (territories (make-hash-table))
          (filecontents (read file)))
      (dolist (territory (getf filecontents :territories))
        (destructuring-bind (key name extra-armies) territory
          (setf (gethash key territories)
                (make-instance 'territory
                               :name name
                               :extra-armies extra-armies))))
      territories))
  
  (defmethod read-map ((path pathname))
  