Draw all nonisomorphic simple graphs with four vertices.

Draw all nonisomorphic simple graphs with four vertices.

Given information:

simple graphs with four vertices.

Calculation:

Two graphs are G and G’ (with vertices V ( G ) and V(G′) respectively and edges E ( G ) and E(G′) respectively) are isomorphic if there exists one-to-one correspondence such that

[u,v] is an edge in G⇔[g(u),g(v)] is an edge of G′.

We are interested in all nonisomorphic simple graphs with 4 vertices.

n = 4

We know that a simple graph with n vertices has most n(n−1)2 edges and thus a simple graph with 4 vertices has at most 4(4−1)2=4⋅32=122=6 edges