{HEAD ~ The first state} of the pump corresponds to {TAIL ~ a first rotational direction} of the pump, and the second state of the pump corresponds to a second rotational direction of the pump 
corresponds to
{ HEAD ~ The first state } of the pump corresponds to { TAIL ~ a first rotational direction } of the pump , and the second state of the pump corresponds to a second rotational direction of the pump
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH 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 OTH OTH