Instance length_getSupport_nz : forall (A : Set)(c : Comp A),
  well_formed_comp c ->
  nz (length (getSupport c)).

Lemma low_tree_approx_same_h : forall n (A : Set)(eqd : eq_dec A)(c : Comp A)(t : DistApproxTree A) ls, dat_correct_h c ls n t -> forall a, well_formed_comp c -> lowDistApprox_ls c a n ls (lowDistApproxFromTree eqd t a).