Fixpoint remove_list_sub {A} (A_eqb : A -> A -> bool) (sublist : list A) (lst : list A) : list A :=
  match sublist with
  | [] => lst
  | h :: t => remove_list_sub A_eqb t (remove_aux A_eqb lst h)
  end.

Lemma map_takeL {A B} (f : A -> B) : forall n l, List.map f (takeL n l) = takeL n (List.map f l).