anchor.diff:    (with-accessors ((ticks ticks) (population population) (tendency hipsterish-tendency) (styles styles) (period period)) object
       (print-unreadable-object (object stream :type t)
         (format stream ":POPULATION ~a :TENDENCY ~4,2f% :STYLES ~a :DELAY ~a @ t = ~a" (length population) (* tendency 100) (length styles) period ticks))))
  +
  +(defmethod print-object ((object foggy-town) stream)
  +  (with-accessors ((ticks ticks) (population population) (tendency hipsterish-tendency) (styles styles) (visibility visibility)) object
  +    (print-unreadable-object (object stream :type t)
  +      (format stream ":POPULATION ~a :TENDENCY ~4,2f% :STYLES ~a :VISIBILITY ~a @ t = ~a"
  +              (length population) (* tendency 100) (length styles) visibility ticks))))
   
   (defgeneric copy-town (town)
     (:documentation "Returns a deep copy of a given town. Useful for when you need to keep the initiator town around.")
  
positive.code:   "List of characters eligible for styles. This can be rebound if you desire more characters.")
  
  ;;; Classes
  
  (defclass town-snapshot ()
    ((ticks :initform 0
  
negative.code:            :documentation "How long before the individuals know the clothing choice of their peers, measured in ticks.")
     (history :initarg :history
              :accessor town-history
              :documentation "The last iterations of the simulation, for use in computing certain future iterations."))
    (:documentation "A town with a temporal delay. Inhabitants are only able to see their popularities from some time ago."))
  
  (defclass foggy-town (town-snapshot)
    ((visibility :initform 4
                 :initarg :visibility
                 :accessor visibility
                 :documentation "How many other other inhabitants that each inhabitant can see."))
    (:documentation "A town with a spatial delay. Inhabitants are only able to see their popularities with reference to a subset of the population."))
  
  ;; Structs are easy but they still need a bit of tweaking.
  (defmethod hipsterish-tendency ((object inhabitant)) (inhabitant-hipsterish-tendency object))
  (defmethod styles ((object inhabitant)) (inhabitant-style object))
  
  ;;; Class constructors
  
  