{HEAD ~ The lower surface} and the upper surface of {TAIL ~ the clasp} do not run parallel to one another 
of
{ HEAD ~ The lower surface } and the upper surface of { TAIL ~ the clasp } do not run parallel to one another
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH