Transparent Z.of_nat.

Corollary combine_upd_Znth1 : forall {A B}{d: Inhabitant B} (l1 : list A) (l2 : list B) i x,
0 <= i < Zlength l1 ->
Zlength l1 = Zlength l2 ->
combine (upd_Znth i l1 x) l2 = upd_Znth i (combine l1 l2) (x, Znth i l2).