TODO:
practise midterm
practise final

tut 6: Let G be a 4-regular graph, and let X be any set of vertices. Prove that the number of edges
in the cut induced by X is even.

tut 9: is this induction on k??

A9q3
A10q4
A5q3,q4

"If G is not
connected, then we can add bridges between components on the outer face to create a
connected graph. We do not create cycles this way, so every cycle has length at least 6,
and we can apply the same upper bound on m."