Figure 18

Supportive illustrations for the proof of Lemma 4. T^a corresponds to the topology in Figure 17(e) (replace z with a in tree T) in all the cases. (a) T^b corresponds to the topology in Figure 17(f) (replace z with b in tree T). (b) T^b corresponds to the topology in Figure 17(b) (replace z with b in tree T). (c) T^b corresponds to the topology in Figure 17(c) (replace z with b in tree T). (d) T^b corresponds to the topology in Figure 17(d) (replace z with b in tree T).