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

Lemma lowDistApprox_left_total : forall (A : Set)(eqd : eq_dec A)(c : Comp A) a, well_formed_comp c -> left_total (lowDistApprox c a).