Definition unfold_reptype' {t} (v: reptype' t): REPTYPE' t :=
  @eq_rect Type (reptype' t) (fun x: Type => x) v (REPTYPE' t) (reptype'_eq t).Definition fold_reptype' {t} (v: REPTYPE' t): reptype' t :=
  @eq_rect_r Type (REPTYPE' t) (fun x: Type => x) v (reptype' t) (reptype'_eq t).

Lemma fold_unfold_reptype': forall t (v: reptype' t), fold_reptype' (unfold_reptype' v) = v.