AND gates of {HEAD ~ the power levels} for controlling {TAIL ~ said realized level combinations} by controlling positions of signal contacts of the three phase contactors by means of said contactor position lines 
for controlling
AND gates of { HEAD ~ the power levels } for controlling { TAIL ~ said realized level combinations } by controlling positions of signal contacts of the three phase contactors by means of said contactor position lines
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH