{HEAD ~ The body} is open at a first or top end and closed at {TAIL ~ a second or bottom end} 
is closed at
{ HEAD ~ The body } is open at a first or top end and closed at { TAIL ~ a second or bottom end }
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL