Module get := fc_get wf weak subst unique.
Unset Implicit Arguments.
Ltac obtacpre :=
intros; simpl in *.
Ltac obtacsolve :=
intros; simpl in *; try solve [ok].

(* More pratical version of these lemma (both forms are useful, though) *)
Lemma get_tpg_correct' : ∀ {G : context} {a A : tm},
AnnTyping G a A → A = get_tpg G a.