“…More formally, we note that the case where p 1 , p 2 and p 3 are distinct is covered by Lemma 2.2. The case when T is regular, that is, when p 1 ¼ p 2 ¼ p 3 ¼ p for some p, was considered by Santos & Felix (2011). In this case, the symmetry group of T is G ¼ Ãp32 and the precise coloring of T is perfect because it corresponds to the partition fgðJtÞ j g 2 Gg of T , where t is the p-gon stabilized by the pfold rotation QR and J is the subgroup hPRQRP; Q; Ri of index 3 in G. The last case is, without loss of generality, when q :¼ p 1 is distinct from 2p :¼ p 2 ¼ p 3 for some integer p. Here G ¼ Ãpq2 and the precise coloring of T is perfect because it corresponds to the partition fGt 1 g [ fgðJt 2 Þ j g 2 Gg of T , where t 1 is any q-gon, t 2 is the 2p-gon stabilized by the p-fold rotation QR, and J is the subgroup hPRP; Q; Ri of index 2 in G. Fig.…”