anchor.diff:  (defmethod asdf:operation-done-p ((o print-op)(c asdf:static-file))
     nil)
   
  +(defmethod asdf:operate ((o print-op)(s asdf:system) &key)
  +  (asdf:perform o s)
  +  (call-next-method))
  +
   (defmethod asdf:operate ((o print-op)(s asdf:module) &key)
     (mapc #'(lambda (spec) (apply #'asdf:perform (list (car spec) (cdr spec))))
       (asdf::traverse o s)))
  
positive.code: (defmethod asdf:perform ((o print-op) c)
    t)
  
  (defmethod asdf:perform ((o print-op)(c asdf:source-file))
    (format t "~&;;; printing source ~A~%" (asdf:component-pathname c))
    (asdf/run-program:run-program
  
negative.code: (import '(cldoc:print-op cldoc:print-system) :cl-user)
  (import '(cldoc:print-op cldoc:print-system) :asdf)
  
  (defun :lpr (system-designator)
    (print-system system-designator))
  
  ;; (print-system :gs.ebu.asdf)
  
  ;;;;;
  