{TAIL ~ The impedance value} is added to {HEAD ~ a series connected resistor} to provide the output impedance 
{ TAIL ~ The impedance value } is added to { HEAD ~ a series connected resistor } to provide the output impedance
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH