Definition typeR (t1: type) (t2: type): Prop := (rank_type cenv_cs t1 < rank_type cenv_cs t2)%nat.

Lemma type_ind: forall P : type -> Prop, (forall t, match t with | Tstruct id => let m := co_members (get_co id) in Forall (fun it => P (snd it)) m | _ => True end -> P t) -> forall t, P t.