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