The discrimination of {TAIL ~ an anomaly} of gas composition of the laser gas can be accomplished by {HEAD ~ simple means} 
The discrimination of { TAIL ~ an anomaly } of gas composition of the laser gas can be accomplished by { HEAD ~ simple means }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD