An arch 40 is formed in the fold of panels 36 and 38 so as to create a downward biasing force on flaps 36 and 38, which holds flaps 36 and 38 in {HEAD ~ contact} with {TAIL ~ base} 32  
with
An arch 40 is formed in the fold of panels 36 and 38 so as to create a downward biasing force on flaps 36 and 38 , which holds flaps 36 and 38 in { HEAD ~ contact } with { TAIL ~ base } 32
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 OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH