Biject the graph to z, drop all odd edges and you get a countably infinite subgraph. The key point is that you’re looking for any subgraph that is complete or edgeless.
Ah! I see.
Biject the graph to z, drop all odd edges and you get a countably infinite subgraph. The key point is that you’re looking for any subgraph that is complete or edgeless.
Ah! I see.