Graph invariant

PAL Definice Invariant grafu

Function $\Phi$ over a graph, for which following holds: $G\text{ is isomorphic with }H\Rightarrow \Phi (G)=\Phi (H)$ Examples

• number of node
• number of vertices
• sum of unique degrees (both in and out), sorted
• sequence of degrees on a path

If invariant doesn’t hold, graphs are not isomorphic.