bp1 path(@S, D, D, P, C)     :-	#link(@S, D, C), P=f_init(S, D)
bp2 path(@S, D, Z, P, C)     :-	#link(@S, Z, C1), path(@Z, D, Z2, P2, C2),
				C=f_compute(C1, C2), P=f_concatePath(S, P2).
bp3 bestPathCost(@S, D, min(C)):- path(@S, D, Z, P, C).
bp4 bestPath(@S, D, P, C)    :-	bestPathCost(@S, D, C), path(@S, D, Z, P, C).
Query bestPath(@S, D, P, C).