anchor.diff:      nil))
   
   
  -(defclass with-id ()
  +
  +;; CLASSES
  +
  +(defclass with-id ()     ; abstract
     ((id
       :initarg :id
       :initform (error ":id missing")
  
positive.code: (in-package :de-sim)
  
  
  (defgeneric next-to-evolve (obj &optional next time)
    (:documentation "Write me"))
  
  
negative.code: 
  
  
  ;; FUNCTIONS AND METHODS
  
  (defun fresh-id ()
    (incf *fresh-id*))
  
  
  (defmethod components-list ((sim simulator))
    (components-of sim))
  
  
  (defmethod imminent-event ((obj object) &optional (max-time nil))
    (declare (ignore max-time))
    nil)
  
  
  (defmethod imminent-event ((ac actor) &optional (max-time nil))
  