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