YES O(n^3) TRS: {app(app(app(compose(), f), g), x) -> app(f, app(g, x))} DUP: We consider a non-duplicating system. Trs: {app(app(app(compose(), f), g), x) -> app(f, app(g, x))} Matrix Interpretation: Interpretation class: triangular [0] [compose] = [0] [0] [X5] [X2] [1 1 0][X5] [1 0 0][X2] [0] [app]([X4], [X1]) = [0 1 0][X4] + [0 1 0][X1] + [1] [X3] [X0] [0 0 0][X3] [0 0 0][X0] [0] Qed