running {HEAD ~ a shortest path algorithm} with the current location and {TAIL ~ the destination location} or the destination region 
with
running { HEAD ~ a shortest path algorithm } with the current location and { TAIL ~ the destination location } or the destination region
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH