adjusting {TAIL ~ a delay} provided by each of the delay stages to attempt to equalize a first time difference and {HEAD ~ a second time difference}, 
adjusting { TAIL ~ a delay } provided by each of the delay stages to attempt to equalize a first time difference and { HEAD ~ a second time difference } ,
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH