{HEAD ~ The first piston} is actuated by {TAIL ~ an external force} for pressurizing hydraulic fluid in the first cylinder 
{ HEAD ~ The first piston } is actuated by { TAIL ~ an external force } for pressurizing hydraulic fluid in the first cylinder
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH