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