(i) Prove that the forcing relation Γ* is an equivalence relation.
(ii) Prove that the following properties hold:
2. The complete graph K2 has two implication classes. Give a formula for for n ≥ 2.
3. Which of the graphs in Figure 5.16 are comparability graphs? How many implication classes and color classes do they have?
4. Let G be a connected comparability graph whose complement is connected ...