Definition is_int32_noattr_type t :=
 match t with
 | Tint I32 _ {| attr_volatile := false; attr_alignas := None |} => True
 | _ => False
 end.

Lemma mapsto_tuint_tint: forall sh, mapsto sh (Tint I32 Unsigned noattr) = mapsto sh (Tint I32 Signed noattr).