YES O(n^3) TRS: {w(r(x)) -> r(w(x)), b(r(x)) -> r(b(x)), b(w(x)) -> w(b(x))} DUP: We consider a non-duplicating system. Trs: {w(r(x)) -> r(w(x)), b(r(x)) -> r(b(x)), b(w(x)) -> w(b(x))} Matrix Interpretation: Interpretation class: triangular [X2] [1 0 1][X2] [0] [b]([X1]) = [0 0 0][X1] + [0] [X0] [0 0 1][X0] [0] [X2] [1 0 1][X2] [0] [w]([X1]) = [0 0 0][X1] + [0] [X0] [0 0 1][X0] [1] [X2] [1 0 0][X2] [0] [r]([X1]) = [0 0 0][X1] + [0] [X0] [0 0 1][X0] [1] Qed