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