anchor.diff:    (stream-draw-ast (body-ast ast) stream)
     (format stream "   ~a -> ~a~%"
   	  (id ast)
  -	  (id (body-ast ast))))
  +	  (id (body-ast ast)))
  +  (stream-draw-ast (argparse-ast ast) stream)
  +  (format stream "   ~a -> ~a~%"
  +	  (id ast)
  +	  (id (argparse-ast ast))))
     
   (defmethod children ((ast function-ast))
     (list (body-ast ast)))
  
positive.code: (defun make-argcount-ast ()
    (make-instance 'argcount-ast))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Class ARG-AST.
  
negative.code: (defun make-arg-ast (index)
    (make-instance 'arg-ast :index index))
  
  (defmethod stream-draw-ast ((ast arg-ast) stream)
    (format stream "   ~a [style = filled, fillcolor = orange];~%" (id ast))
    (format stream "   ~a [label = \"~a\"];~%"
  	  (id ast)
  	  (index ast)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Class HALT-AST.
  