anchor.diff:    of obj."))
   
   
  -(defgeneric schedule (actor function &key at relative-p)
  +(defgeneric schedule (delay function actor &rest args)
     (:documentation "TODO"))
   
   
  
positive.code: 	       #'< :key #'time-of)))
  
  
  (defmethod schedule ((act actor) (fn function)
  		     &key (at 0) (relative-p t) (id 0 id-p))
    (declare (time-type at)
  	   (id-type id))
  
    (let ((abs-time (+ at (if relative-p
  			    (gettime)
  			    0))))
      (if (< abs-time (gettime))
  	(error 'error-invalid)
  	(setf (events-of act)
  	      (sort (cons (make-instance 'event
  					 :id (if id-p
  						 id
  						 (fresh-id))
  					 :time abs-time :fn fn)
  			  (events-of act))
  		    #'< :key #'time-of))))
    act)
  
  
  (defmethod evolve ((obj object))
  
negative.code:     :initarg :fn
      :initform (error ":action missing")
      :accessor fn-of
      :type function)
     (args
      :initarg :args
      ;; unbound if unused
      :accessor args-of
      :type list)))
  
  
  
  (defclass object (with-id)
  