{HEAD ~ a second counter} receiving {TAIL ~ an output} of said second multiplexer and outputting a second count signal, 
{ HEAD ~ a second counter } receiving { TAIL ~ an output } of said second multiplexer and outputting a second count signal ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH