 generating {TAIL ~ a negative transition} in {HEAD ~ response} to the signal selected in sub step B 3 
generating { TAIL ~ a negative transition } in { HEAD ~ response } to the signal selected in sub step B 3
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH