MAYBE MAYBE TRS: { incr(X) -> n__incr(X), incr(nil()) -> nil(), incr(cons(X, L)) -> cons(s(X), n__incr(activate(L))), activate(X) -> X, activate(n__incr(X)) -> incr(X), activate(n__adx(X)) -> adx(X), activate(n__zeros()) -> zeros(), adx(X) -> n__adx(X), adx(nil()) -> nil(), adx(cons(X, L)) -> incr(cons(X, n__adx(activate(L)))), zeros() -> cons(0(), n__zeros()), zeros() -> n__zeros(), nats() -> adx(zeros()), head(cons(X, L)) -> X, tail(cons(X, L)) -> activate(L) } DUP: We consider a non-duplicating system. Trs: { incr(X) -> n__incr(X), incr(nil()) -> nil(), incr(cons(X, L)) -> cons(s(X), n__incr(activate(L))), activate(X) -> X, activate(n__incr(X)) -> incr(X), activate(n__adx(X)) -> adx(X), activate(n__zeros()) -> zeros(), adx(X) -> n__adx(X), adx(nil()) -> nil(), adx(cons(X, L)) -> incr(cons(X, n__adx(activate(L)))), zeros() -> cons(0(), n__zeros()), zeros() -> n__zeros(), nats() -> adx(zeros()), head(cons(X, L)) -> X, tail(cons(X, L)) -> activate(L) } Fail