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