anchor.diff:    (loop for next in (successors instruction)
   	do (format stream
   		   "  ~a -> ~a [style = bold];~%"
  -		   (gethash instruction *instruction-table*)
  +		   (unique-id instruction)
   		   (gethash next *instruction-table*))))
     
   (defmethod draw-instruction (instruction stream)
     (format stream "   ~a [label = \"~a\"];~%"
  -	  (gethash instruction *instruction-table*)
  +	  (unique-id instruction)
   	  (class-name (class-of instruction))))
   
   (defmethod draw-instruction :after (instruction stream)
  
positive.code: 
  (defmethod draw-instruction ((instruction s+-instruction) stream)
    (format stream "   ~a [label = \"s+\"];~%"
  	  (gethash instruction *instruction-table*)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  
negative.code: 
  (defmethod draw-instruction ((instruction u<-instruction) stream)
    (format stream "   ~a [label = \"u<\"];~%"
  	  (unique-id instruction)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  