{HEAD ~ The cover} is affixed to {TAIL ~ the base} such that the fold between each flap portion and the cover is arched upwardly away from the base to create a downward biasing force on each flap portion 
is affixed to
{ HEAD ~ The cover } is affixed to { TAIL ~ the base } such that the fold between each flap portion and the cover is arched upwardly away from the base to create a downward biasing force on each flap portion
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL 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 OTH OTH OTH OTH OTH OTH OTH OTH