fact: Fixpoint it_i' (i : nat) (n : nat) (x : X) : X := match n with | 0 => x | S n' => f i (it_i' (S i) n' x) end.
imports: Ascii String Undecidability.L(Util.L_facts) MetaCoq(Template.All Template.Checker) Undecidability.Shared.Libs.PSL.Base MetaCoq.Utils.bytestring