// this is a comment routes[a2, min_cost(cost_pair)] := [a airport.iata 'LHR'], :flies_to[a, a2, dist], [a2 airport.iata dst], path <- ['LHR', dst], cost_pair <- [path, dist]; routes[a2, min_cost(cost_pair)] := routes[a, prev], :flies_to[a, a2, dist], [a2 airport.iata dst], path <- append(first(prev), dst), cost_pair <- [path, last(prev) + dist]; ?[cost, path] := routes[dst, cost_pair], cost <- last(cost_pair), path <- first(cost_pair); :order -cost; :limit 10;