Lemma 24.10(Triangle inequality) Let G=(V,E)be a weighted,directed graph with weight function w:ER and source vertex s.Then,for all edges (u,v)E,we have 8s,)≤8s,0)+w(u,). Prof Suppose that pis a shortest pat from sourcesto vertexv.Then p has no more weight than any other path fromsto.Specifically,path phas no more weight than the particular path that takes a shortest path from soucestovertex and then takes edge ()