so that {HEAD ~ the input} to said feedback element is either the data input signal or {TAIL ~ a combination} thereof with the output of the feedback element, as determined by said control signal 
is
so that { HEAD ~ the input } to said feedback element is either the data input signal or { TAIL ~ a combination } thereof with the output of the feedback element , as determined by said control signal
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH