(* not this version! Lemma sublist_list_repeat {A} i j k (v:A) (I: 0<=i) (IJK: (Z.to_nat i <= Z.to_nat j <= k)%nat): sublist i j (list_repeat k v) = list_repeat (Z.to_nat (j-i)) v. *)

Lemma Zlength_list_repeat:
forall {A} n (x: A),
0 <= n ->
Zlength (list_repeat (Z.to_nat n) x) = n.