The first state of {HEAD ~ 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 
The first state of { HEAD ~ 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
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH 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