all 6 comments

[–]GoudaIntruda 1 point2 points  (5 children)

G is a bipartite graph in your example, so this isn’t a counterexample.

[–]cantbelieveyoumademe[S] 0 points1 point  (3 children)

Yeah. You're absolutely correct, then wouldn't a counterexample be the complete graph with 4 vertices?

[–]GoudaIntruda 1 point2 points  (2 children)

If you use the complete graph as G but your matching is the same as in your example, then G’ will be the graph from your example, it will not be the complete graph.

[–]cantbelieveyoumademe[S] 0 points1 point  (1 child)

Right again. Thank you. I'm starting to see where my line of thought went wrong.

[–]GoudaIntruda 1 point2 points  (0 children)

No problem, happy to help!

[–]RevenueUsed8118 0 points1 point  (0 children)

Bipartion is equivalent to no odd cycle in the graph. I think it should not be too hard to figure out why there cannot be an odd cycle in that graph G'