In one embodiment, {HEAD ~ additional supporting elements} are provided besides {TAIL ~ the supporting element} of the end part 
are provided besides
In one embodiment , { HEAD ~ additional supporting elements } are provided besides { TAIL ~ the supporting element } of the end part
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH