If there is no existing lock on F2, {HEAD ~ a lock} on {TAIL ~ the additional feature instance} F2 is set 608 as requested, and the identifier TID1 owned by the session S1 is associated with the lock L1 and L2 on feature instances F1 and F2, respectively 
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If there is no existing lock on F2 , { HEAD ~ a lock } on { TAIL ~ the additional feature instance } F2 is set 608 as requested , and the identifier TID1 owned by the session S1 is associated with the lock L1 and L2 on feature instances F1 and F2 , respectively
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH