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