In addition to, or in lieu of, distance, {HEAD ~ an estimated time} to {TAIL ~ the current location} of the first mobile user can be provided or the time to convergence can be presented  
to
In addition to , or in lieu of , distance , { HEAD ~ an estimated time } to { TAIL ~ the current location } of the first mobile user can be provided or the time to convergence can be presented
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH