Thus, not only does the data identify whether a selected event occurred, but {HEAD ~ the data} also indicates {TAIL ~ an exact sequence} of the order that the events occurred 
indicates
Thus , not only does the data identify whether a selected event occurred , but { HEAD ~ the data } also indicates { TAIL ~ an exact sequence } of the order that the events occurred
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH