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