wherein * denotes the point of attachment of T1 to COUP and ** denotes {HEAD ~ the point} of {TAIL ~ attachment} to T2  
of
wherein * denotes the point of attachment of T1 to COUP and * * denotes { HEAD ~ the point } of { TAIL ~ attachment } to T2
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH