{HEAD ~ The sequencer} 12 is controlled by {TAIL ~ sequencer control apparatus} 14, which contains the components required to direct two electric motors contained in the sequencer 12 to perform the vertical and horizontal rotations described above 
is controlled by
{ HEAD ~ The sequencer } 12 is controlled by { TAIL ~ sequencer control apparatus } 14 , which contains the components required to direct two electric motors contained in the sequencer 12 to perform the vertical and horizontal rotations described above
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL 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 OTH OTH OTH OTH OTH OTH OTH OTH