No credit card required
Figure 5-15. A bipartite graph Γ(A).
5.5.10 Proposition. We have
5.5.11 Corollary. We have
Proof. Put ti, = 1 in (5.80) to obtain
Similarly put t1 = 0 and t2 = t3 = ... = 1 (or use (5.79) directly) to obtain (5.81).
A famous problem that goes back to Euler asks for what graphs G there is a closed walk ...