(* -------------------------------------------------------------- *)

(* Specifications: *)
Lemma DefEq_conv : forall G D a b A B, DefEq G D a b A ->
DefEq G (dom G) A B a_Star -> DefEq G D a b B.
Lemma trans_iso : forall G D phi1 phi2 phi3,
Iso G D phi1 phi2 -> Iso G D phi2 phi3 -> Iso G D phi1 phi3.
Lemma iso_cong : forall G D A A' B B' T T',
DefEq G D A A' T -> DefEq G D B B' T -> DefEq G D T T' a_Star ->
Iso G D (Eq A B T) (Eq A' B' T').