{HEAD ~ A subtracting unit} subtracts {TAIL ~ the input signal} from the first delayed signal to generate a difference signal 
subtracts
{ HEAD ~ A subtracting unit } subtracts { TAIL ~ the input signal } from the first delayed signal to generate a difference signal
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH