MAYBE MAYBE TRS: { q(0()) -> 0(), q(s(X)) -> s(p(q(X), d(X))), t(N) -> cs(r(q(N)), nt(ns(N))), t(X) -> nt(X), s(X) -> ns(X), p(X, 0()) -> X, p(0(), X) -> X, p(s(X), s(Y)) -> s(s(p(X, Y))), d(0()) -> 0(), d(s(X)) -> s(s(d(X))), f(X1, X2) -> nf(X1, X2), f(0(), X) -> nil(), f(s(X), cs(Y, Z)) -> cs(Y, nf(X, a(Z))), a(X) -> X, a(nt(X)) -> t(a(X)), a(ns(X)) -> s(a(X)), a(nf(X1, X2)) -> f(a(X1), a(X2)) } DUP: We consider a duplicating system. Trs: { q(0()) -> 0(), q(s(X)) -> s(p(q(X), d(X))), t(N) -> cs(r(q(N)), nt(ns(N))), t(X) -> nt(X), s(X) -> ns(X), p(X, 0()) -> X, p(0(), X) -> X, p(s(X), s(Y)) -> s(s(p(X, Y))), d(0()) -> 0(), d(s(X)) -> s(s(d(X))), f(X1, X2) -> nf(X1, X2), f(0(), X) -> nil(), f(s(X), cs(Y, Z)) -> cs(Y, nf(X, a(Z))), a(X) -> X, a(nt(X)) -> t(a(X)), a(ns(X)) -> s(a(X)), a(nf(X1, X2)) -> f(a(X1), a(X2)) } Fail