Arguments eq_dec _ _ _ _ : simpl never.

Lemma list_Znth_eq' : forall {A} {d: Inhabitant A} (l1 l2 : list A)
(Hlen : Zlength l1 = Zlength l2)
(Heq : forall j, 0 <= j < Zlength l1 -> Znth j l1 = Znth j l2), l1 = l2.