YES O(n^3) TRS: { g(ok(X)) -> ok(g(X)), h(mark(X)) -> mark(h(X)), h(ok(X)) -> ok(h(X)), f(mark(X)) -> mark(f(X)), f(ok(X)) -> ok(f(X)), active(h(X)) -> h(active(X)), active(f(X)) -> mark(g(h(f(X)))), active(f(X)) -> f(active(X)), proper(g(X)) -> g(proper(X)), proper(h(X)) -> h(proper(X)), proper(f(X)) -> f(proper(X)), top(mark(X)) -> top(proper(X)), top(ok(X)) -> top(active(X)) } DUP: We consider a non-duplicating system. Trs: { g(ok(X)) -> ok(g(X)), h(mark(X)) -> mark(h(X)), h(ok(X)) -> ok(h(X)), f(mark(X)) -> mark(f(X)), f(ok(X)) -> ok(f(X)), active(h(X)) -> h(active(X)), active(f(X)) -> mark(g(h(f(X)))), active(f(X)) -> f(active(X)), proper(g(X)) -> g(proper(X)), proper(h(X)) -> h(proper(X)), proper(f(X)) -> f(proper(X)), top(mark(X)) -> top(proper(X)), top(ok(X)) -> top(active(X)) } Matrix Interpretation: Interpretation class: triangular [X2] [1 0 3][X2] [0] [top]([X1]) = [0 0 0][X1] + [0] [X0] [0 0 0][X0] [0] [X2] [1 3 3][X2] [0] [ok]([X1]) = [0 1 0][X1] + [2] [X0] [0 0 1][X0] [3] [X2] [1 1 0][X2] [2] [proper]([X1]) = [0 1 0][X1] + [0] [X0] [0 0 0][X0] [0] [X2] [1 3 3][X2] [3] [active]([X1]) = [0 1 0][X1] + [0] [X0] [0 0 1][X0] [1] [X2] [1 0 3][X2] [0] [f]([X1]) = [0 1 0][X1] + [2] [X0] [0 0 1][X0] [0] [X2] [1 0 2][X2] [0] [h]([X1]) = [0 1 0][X1] + [1] [X0] [0 0 1][X0] [0] [X2] [1 1 1][X2] [0] [g]([X1]) = [0 1 0][X1] + [1] [X0] [0 0 1][X0] [0] [X2] [1 1 0][X2] [0] [mark]([X1]) = [0 0 0][X1] + [0] [X0] [0 0 1][X0] [1] Qed