Two empty graphs: ( ) Two singleton graphs: ( 0 ) Empty and singleton graphs: Singleton and empty graphs: ( ) Ring with add vertex and edge (ring+) and ring: ( 0 1 2 3 5 ) ( 0 5 3 2 1 ) ( 1 0 5 3 2 ) ( 1 2 3 5 0 ) ( 2 1 0 5 3 ) ( 2 3 5 0 1 ) ( 3 2 1 0 5 ) ( 3 5 0 1 2 ) ( 5 0 1 2 3 ) ( 5 3 2 1 0 ) Ring+ and ring, directed: ( 0 1 2 3 5 ) ( 1 2 3 5 0 ) ( 2 3 5 0 1 ) ( 3 5 0 1 2 ) ( 5 0 1 2 3 ) Ring+ and ring where node parity should be equal: Ring+ and ring where edge parity should be equal: ( 1 0 5 3 2 ) ( 1 2 3 5 0 ) Ring+ and ring with only one vertex coloring: ( 0 1 2 3 5 ) ( 0 5 3 2 1 ) ( 1 0 5 3 2 ) ( 1 2 3 5 0 ) ( 2 1 0 5 3 ) ( 2 3 5 0 1 ) ( 3 2 1 0 5 ) ( 3 5 0 1 2 ) ( 5 0 1 2 3 ) ( 5 3 2 1 0 ) Ring+ and ring with vertex coloring: ( 0 1 2 3 5 ) ( 5 3 2 1 0 ) Ring+ and ring with edge coloring: ( 0 1 2 3 5 ) ( 0 5 3 2 1 ) Ring+ and ring where node of graph 1 should not be 3 higher than node of graph 2: ( 0 1 2 3 5 ) ( 0 5 3 2 1 ) ( 1 2 3 5 0 ) ( 2 1 0 5 3 ) ( 5 0 1 2 3 ) ( 5 3 2 1 0 ) Ring+ and ring with different directedness.