Definition AnnGood G D := Good (erase_context G) D.

(* Specifications: *)
Lemma AnnGoodIsGood : forall G D, AnnGood G D -> Good (erase_context G) D.
Lemma AnnGoodnil : AnnGood nil AtomSetImpl.empty.
unfold AnnGood. simpl. unfold Good. unfold erased_context.