The outputs of {TAIL ~ the individual power sources} are responsive and proportional to {HEAD ~ individual input control signals} 
The outputs of { TAIL ~ the individual power sources } are responsive and proportional to { HEAD ~ individual input control signals }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD