{HEAD ~ The magnitude} of delay is varied between these two extremes by varying the relative levels of operation of the differential sections D1 and {TAIL ~ D2} 
{ HEAD ~ The magnitude } of delay is varied between these two extremes by varying the relative levels of operation of the differential sections D1 and { TAIL ~ D2 }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL