YES We show the termination of R/S, where R is t(f(x),g(y),f(z)) -> t(z,g(x),g(y)) t(g(x),g(y),f(z)) -> t(f(y),f(z),x) and S is: f(g(x)) -> g(f(x)) g(f(x)) -> f(g(x)) f(f(x)) -> g(g(x)) g(g(x)) -> f(f(x)) Since R almost dominates S and S is non-duplicating, it is enough to show finiteness of (P, Q). Here P consists of the dependency pairs t#(f(x),g(y),f(z)) -> t#(z,g(x),g(y)) t#(g(x),g(y),f(z)) -> t#(f(y),f(z),x) and Q consists of the rules: t(f(x),g(y),f(z)) -> t(z,g(x),g(y)) t(g(x),g(y),f(z)) -> t(f(y),f(z),x) f(g(x)) -> g(f(x)) g(f(x)) -> f(g(x)) f(f(x)) -> g(g(x)) g(g(x)) -> f(f(x)) The weakly monotone algebra (N, >) with t#_A(x1,x2,x3) = x1 + x2 + x3 f_A(x1) = x1 + 1 g_A(x1) = x1 + 1 t_A(x1,x2,x3) = 0 strictly orients the following dependency pairs: t#(f(x),g(y),f(z)) -> t#(z,g(x),g(y)) t#(g(x),g(y),f(z)) -> t#(f(y),f(z),x) We remove them from the set of dependency pairs. No dependency pair remains.