{HEAD ~ An adding unit} adds {TAIL ~ the reference signal} to the filtered signal to generate an output signal 
adds
{ HEAD ~ An adding unit } adds { TAIL ~ the reference signal } to the filtered signal to generate an output 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