{HEAD ~ A belt} is extendable from {TAIL ~ the retractor} and retractable by the retractor 
is extendable from
{ HEAD ~ A belt } is extendable from { TAIL ~ the retractor } and retractable by the retractor
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH