induction ls; intuition; simpl in *.
destruct (in_dec eqd a (getUnique ls eqd)).
destruct ls; simpl in *; intuition.
simpl.
omega.
Qed.
Definition maxList(ls : list nat) : nat :=
fold_left max ls O.

(* Specifications: *)
Lemma fold_left_max_ge_init : forall (ls : list nat)(n : nat),
fold_left max ls n >= n.