Navigation  without Java Scripts

Source Code for Simple Routing Problem

DOMAINS
  town     = symbol
  distance = integer

PREDICATES
  nondeterm road(town,town,distance)
  nondeterm route(town,town,distance)

CLAUSES
  road("tampa","houston",200).
  road("gordon","tampa",300).
  road("houston","gordon",100).
  road("houston","kansas_city",120).
  road("gordon","kansas_city",130).

  route(Town1,Town2,Distance):-
        road(Town1,Town2,Distance).
  route(Town1,Town2,Distance):-
        road(Town1,X,Dist1),
        route(X,Town2,Dist2),
        Distance=Dist1+Dist2,
        !.

GOAL    route("tampa", "kansas_city", X),
        write("Distance from Tampa to Kansas City is ",X),nl.