(LETREC GETFRINGE
	(GETFRINGE LAMBDA (TR)
		(IF (EQ TR (QUOTE NIL)) (QUOTE NIL)
			(IF (EQ (CDR TR) (QUOTE NIL)) 
				(IF (EQ (CDR (CDR TR)) (QUOTE NIL))
					(CONS (CAR TR) (QUOTE NIL))
					(GETFRINGE (CAR (CDR (CDR TR)))))
				(IF (EQ (CDR (CDR TR)) (QUOTE NIL)) 
					(GETFRINGE (CAR (CDR TR)))
					(APPEND (GETFRINGE (CAR (CDR TR))) 
						    (GETFRINGE (CAR (CDR (CDR TR)))))))))
	(APPEND LAMBDA (X Y)
		(IF (EQ X (QUOTE NIL))  Y
			(CONS (CAR X) (APPEND (CDR X) Y)))))&