Definition gvar_info_eq {V1 V2} (v1: option (globvar V1)) (v2: option (globvar V2)) :=
  match v1, v2 with
    None, None => True
  | Some i1, Some i2 => gvar_init i1 = gvar_init i2 /\
                        gvar_readonly i1 = gvar_readonly i2 /\ gvar_volatile i1 = gvar_volatile i2
  | _, _ => False
  end.Definition gvar_infos_eq {F1 V1 F2 V2}
  (g1 : Genv.t F1 V1) (g2 : Genv.t F2 V2) :=
  forall b, gvar_info_eq (Genv.find_var_info g1 b) (Genv.find_var_info g2 b).

Lemma gvar_info_refl V v: @gvar_info_eq V V v v.