intuition.
simpl in *.
apply in_getUnique_if in H.
eapply in_flatten in H.
destruct H.
intuition.
apply in_map_iff in H0.
destruct H0.
intuition.
subst.
econstructor.
intuition;
eauto.
Qed.
Ltac pairInv :=
match goal with
| [H : (_, _) = (_, _) |-_ ] => inversion H; clear H; subst
end.
Ltac destruct_exists :=
match goal with
| [H : exists x, _ |- _ ] =>
destruct H
end.

Theorem getSupport_In_Ret :
forall (A : Set)(eqd : eq_dec A) x a,
In x (getSupport (Ret eqd a)) ->
x = a.