In the case of a positive logic signal, the signal is active high where {HEAD ~ the logically true state} corresponds to {TAIL ~ a logic level} one 
In the case of a positive logic signal , the signal is active high where { HEAD ~ the logically true state } corresponds to { TAIL ~ a logic level } one
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH