{HEAD ~ Reflux} to the high pressure column 108 is provided by {TAIL ~ reboiler/condenser} 110 
is provided by
{ HEAD ~ Reflux } to the high pressure column 108 is provided by { TAIL ~ reboiler / condenser } 110
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH