Definition true_expr : Clight.expr := Clight.Econst_int Int.one (Tint I32 Signed noattr).

Lemma safe_step_forward {Espec: OracleKind}: forall psi n ora st m, cl_at_external st = None -> jsafeN (@OK_spec Espec) psi (S n) ora st m -> exists st', exists m', jstep (cl_core_sem psi) st m st' m' /\ jm_bupd ora (jsafeN (@OK_spec Espec) psi n ora st') m'.