A support element may be a first elongated element and {HEAD ~ a second elongated element} engaged to {TAIL ~ the first elongated element} 
A support element may be a first elongated element and { HEAD ~ a second elongated element } engaged to { TAIL ~ the first elongated element }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL