4Graph G1 = (V 1,E1) is isomorphic to graph G2 = (V 2,E2) if there is an isomorphism π : V 1 → V 2 (a 1-1 and onto
function) such that (∀u,v 
V 1)((u,v) E1 ⇔ (π(u),π(v)) E2).
4Graph G1 = (V 1,E1) is isomorphic to graph G2 = (V 2,E2) if there is an isomorphism π : V 1 → V 2 (a 1-1 and onto
function) such that (∀u,v V 1)((u,v) E1 ⇔ (π(u),π(v)) E2).