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Wu [9] obtained its critical frontier 

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under a homogeneity assumption. 

The critical point in the case of q = 2 computed from (6) is exact. Wu [9] also used (6) to compute Potts thresholds for the 3-12 and the ( $^{m}$× m ) : ( $^{n}$× n ) kagome-type subnet lattices for $^{m,n}$≤ 4 for which the exact thresholds are not known. In addition, Wu deduced the known exact threshold of site percolation on the 3-12 lattice by considering the Potts model on the (2 × 2) : (2 × 2) kagome-type lattice as shown in Fig. 5. In this case the homogeneity assumption turns out to give the exactly known critical frontier. 

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