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