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