(** ** Properties of [replace] *)

Lemma nth_order_replace_neq A: forall n k1 k2, k1 <> k2 ->
forall (v : t A n) a (H1 : k1 < n) (H2 : k2 < n),
nth_order (replace v (Fin.of_nat_lt H2) a) H1 = nth_order v H1.