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