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