induction n; intuition; simpl in *.
destruct H; subst; intuition.
apply in_app_or in H;
destruct H;
apply in_map_iff in H;
destruct H;
intuition;
subst;
simpl;
f_equal;
eapply IHn; eauto.
Qed.

Lemma getAllBlists_length_In : forall n ls,
length ls = n ->
In ls (getAllBlists n).