1-2-3 Conjecture

1-2-3 Conjecture is a graph G = (V, E). It is is simple, finite, and undirected. You see the triangle. This is ∅=0.

u,v∈V(G)

u and v are any adjacent vertices. The sum of weights of edges incident to u differs from the sum of weights of edges incident to v. Then, the edges of G may be assigned weights from the set {1, 2, 3}. This is 1-2-3 Conjecture. You can color the proper vertexes.