feat(init.{equiv|ua}): remove duplicated theorem

hott/init/equiv.hlean

@@ -254,6 +254,10 @@ namespace is_equiv
     (p : x = y) : (is_equiv (transport P p)) :=
   is_equiv.mk _ (transport P p⁻¹) (tr_inv_tr p) (inv_tr_tr p) (tr_inv_tr_lemma p)
 
+  -- a version where the transport is a cast. Note: A and B live in the same universe here.
+  definition is_equiv_cast [constructor] {A B : Type} (H : A = B) : is_equiv (cast H) :=
+  is_equiv_tr (λX, X) H
+
   section
   variables {A : Type} {B C : A → Type} (f : Π{a}, B a → C a) [H : Πa, is_equiv (@f a)]
             {g : A → A} {g' : A → A} (h : Π{a}, B (g' a) → B (g a)) (h' : Π{a}, C (g' a) → C (g a))
@@ -355,6 +359,10 @@ namespace equiv
   definition equiv_of_eq [constructor] {A B : Type} (p : A = B) : A ≃ B :=
   equiv.mk (cast p) !is_equiv_tr
 
+  definition equiv_of_eq_refl [reducible] [unfold_full] (A : Type)
+    : equiv_of_eq (refl A) = equiv.refl A :=
+  idp
+
   definition eq_of_fn_eq_fn (f : A ≃ B) {x y : A} (q : f x = f y) : x = y :=
   (left_inv f x)⁻¹ ⬝ ap f⁻¹ q ⬝ left_inv f y
 

hott/init/ua.hlean

@@ -10,24 +10,6 @@ prelude
 import .equiv
 open eq equiv is_equiv
 
---Ensure that the types compared are in the same universe
-section
-  universe variable l
-  variables {A B : Type.{l}}
-
-  definition is_equiv_cast [constructor] (H : A = B) : is_equiv (cast H) :=
-  is_equiv_tr (λX, X) H
-
-  definition equiv_of_eq [constructor] (H : A = B) : A ≃ B :=
-  equiv.mk _ (is_equiv_cast H)
-
-  definition equiv_of_eq_refl [reducible] [unfold_full] (A : Type)
-    : equiv_of_eq (refl A) = equiv.refl A :=
-  idp
-
-
-end
-
 axiom univalence (A B : Type) : is_equiv (@equiv_of_eq A B)
 
 attribute univalence [instance]