MAYBE MAYBE TRS: { activate(X) -> X, and(tt(), X) -> activate(X), plus(N, 0()) -> N, plus(N, s(M)) -> s(plus(N, M)), x(N, 0()) -> 0(), x(N, s(M)) -> plus(x(N, M), N) } DUP: We consider a duplicating system. Trs: { activate(X) -> X, and(tt(), X) -> activate(X), plus(N, 0()) -> N, plus(N, s(M)) -> s(plus(N, M)), x(N, 0()) -> 0(), x(N, s(M)) -> plus(x(N, M), N) } Fail