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