Moving the vent location to either side of the vent follower causes {HEAD ~ fluid} or gas to escape from one or {TAIL ~ the other cell} 
to escape from
Moving the vent location to either side of the vent follower causes { HEAD ~ fluid } or gas to escape from one or { TAIL ~ the other cell }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL