intuition.
eapply low_tree_approx_same_inv_h.
eauto.
eapply lowDistApprox_ls_impl.
trivial.
Qed.

(* Specifications: *)
Theorem getSupport_not_In_lowDistApprox : forall n (A : Set)(c : Comp A)(a : A) r,
~In a (getSupport c) ->
lowDistApprox c a n r ->
r == 0.