{TAIL ~ the output} of the selector element is coupled to {HEAD ~ either the first or the second input} of the selector element as determined by said control signal, and 
{ TAIL ~ the output } of the selector element is coupled to { HEAD ~ either the first or the second input } of the selector element as determined by said control signal , and
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH