Module ext_subst (weak : ext_weak_sig) <: ext_subst_sig.
Include weak.
induction G2; [ | inversion 1]; simpl; auto.
Qed.

Lemma binds_to_PropWff: forall G0 A B T c,
Ctx G0 ->
binds c (Co (Eq A B T)) G0 -> PropWff G0 (Eq A B T).