An adder generates {HEAD ~ a final control signal} by adding {TAIL ~ the first and the second control signals} and provides the final control signal to the plant, wherein the final control signal is used to control the plant 
by adding
An adder generates { HEAD ~ a final control signal } by adding { TAIL ~ the first and the second control signals } and provides the final control signal to the plant , wherein the final control signal is used to control the plant
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH