a searching unit to search {HEAD ~ the route information} of {TAIL ~ the respective links} connected via the respective node corresponding to the starting position; and 
of
a searching unit to search { HEAD ~ the route information } of { TAIL ~ the respective links } connected via the respective node corresponding to the starting position ; and
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