2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27953Duality relations for the correlation functions of $n$ sites on the boundary of a planar lattice are derived for the $(N_α, N_β)$ model of Domany and Riedel for $n=2,3$. Our result holds for arbitrary lattices which can have nonuniform interactions.6 pages in RevTeX, 1 ps figure, accepted by Chin. J. Phys. 36 (1998)Statistical Mechanicstext