comparing {HEAD ~ the types} of {TAIL ~ the necessary optical parts} with the types of the installed optical parts which have been identified by the sensors to recognize at least one mismatched optical part; and 
comparing { HEAD ~ the types } of { TAIL ~ the necessary optical parts } with the types of the installed optical parts which have been identified by the sensors to recognize at least one mismatched optical part ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH