YES O(n^4) TRS: {f(X) -> g()} DUP: We consider a non-duplicating system. Trs: {f(X) -> g()} Matrix Interpretation: Interpretation class: triangular [X3] [1 0 0 0][X3] [1] [X2] [0 0 0 0][X2] [0] [f]([X1]) = [0 0 0 0][X1] + [0] [X0] [0 0 0 0][X0] [1] [0] [0] [g] = [0] [0] Qed