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