YES O(n^2) TRS: {g(x, a(), b()) -> g(b(), b(), a())} DUP: We consider a non-duplicating system. Trs: {g(x, a(), b()) -> g(b(), b(), a())} Matrix Interpretation: Interpretation class: triangular [0] [a] = [0] [0] [b] = [1] [X5] [X3] [X1] [1 0][X5] [1 0][X3] [1 1][X1] [0] [g]([X4], [X2], [X0]) = [0 0][X4] + [0 0][X2] + [0 0][X0] + [0] Qed