Transparent Z.of_nat.

Lemma Forall2_upd_Znth_r : forall {A B}{d: Inhabitant A} (P : A -> B -> Prop) l1 l2 i x, Forall2 P l1 l2 ->
P (Znth i l1) x -> 0 <= i < Zlength l1 -> Forall2 P l1 (upd_Znth i l2 x).