Lemma 24.10(Triangle inequality) Let G =(V,E)be a weighted,directed graph with weight function w E-R and source vertex s.Then,for all edges (u,v)EE,we have 8(s,v)≤6(s,u)+w(u,v). W(u,) &(S,U) &(s,)s u v &(s,u) &(s,v) w(u,v)