induction n; intuition; simpl in *.
econstructor.
econstructor.
trivial.
eapply rel_map_app.
eapply rel_map_map2.
eapply rel_map_impl; eauto; intuition.
subst.
rewrite rev_unit.
trivial.
eapply rel_map_map2.
eapply rel_map_impl; eauto; intuition.
subst.
rewrite rev_unit.
trivial.
Qed.

(* Specifications: *)
Lemma getAllBlists_app_In_length : forall n ls,
In ls (getAllBlists_app n) ->
length ls = n.