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