{HEAD ~ The structure} 28 is {TAIL ~ a large structure} having a gallery 31 formed therein 
is
{ HEAD ~ The structure } 28 is { TAIL ~ a large structure } having a gallery 31 formed therein
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH