diff --git a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l1_t03.dart b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l1_t03.dart
index 95fd9837cd..cb41d3d2e0 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l1_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l1_t03.dart
@@ -44,6 +44,8 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for the class with
  * [typedef G<X> = X Function(X)] parameter (invariant case).
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +54,8 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<X>>> {}
 
+typedef expected = A<A<dynamic> Function(A<dynamic>)>;
+
 main() {
-  Expect.equals(
-    typeOf<A<G<A<dynamic>>>>(),
-    typeOf<A>()
-  );
+  Expect.equals(expected, A);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t03.dart b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t03.dart
index 371cb28e22..9af5b5971a 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t03.dart
@@ -44,6 +44,8 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for [typedef G<X> =
  * Function(X)], [class A<X extends G<A<X, Y>>, Y extends X>] (covariant)
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +54,8 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<X, Y>>, Y extends X> {}
 
+typedef expected = A<A<dynamic, dynamic> Function(A<dynamic, dynamic>), dynamic>;
+
 main() {
-  Expect.equals(
-      typeOf<A<G<A<dynamic, dynamic>>, dynamic>>(),
-      typeOf<A>()
-  );
+  Expect.equals(expected, A);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t07.dart b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t07.dart
index b170ff467e..c533aadb97 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t07.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/dynamic/class_typedef_l2_t07.dart
@@ -44,6 +44,8 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for [typedef G<X> =
  * X Function(X)], [class A<X extends G<A<X, Y>>, Y extends X>] (invariant)
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +54,9 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<Y, X>>, Y extends G<A<X, Y>>> {}
 
+typedef expected = A<A<dynamic, dynamic> Function(A<dynamic, dynamic>),
+    A<dynamic, dynamic> Function(A<dynamic, dynamic>)>;
+
 main() {
-  Expect.equals(
-      typeOf<A<G<A<dynamic, dynamic>>,G<A<dynamic, dynamic>>>>(),
-      typeOf<A>()
-  );
+  Expect.equals(expected, A);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l1_t03.dart b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l1_t03.dart
index 28946d0b7d..030e488557 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l1_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l1_t03.dart
@@ -44,7 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for [typedef G<X> =
  * Function(X)], [class A<X extends G<A<X, Y>>, Y extends X>] (covariant)
- * @Issue 41963, 41964
+ *
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 import "../../../../Utils/expect.dart";
@@ -52,68 +55,9 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<X>>> {}
 
-void test(A source) {
-  var fsource = toF(source);
-
-  F<A<G<A<dynamic>>>> target = fsource;
-
-  F<A<G<A<Never>>>> target0 = fsource;
-//                            ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Null>>>> target1 = fsource;
-//                           ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<dynamic>> target2 = fsource;
-//                        ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<dynamic>>> target3 = fsource;
-//                           ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<dynamic>>>>> target4 = fsource;
-//                                 ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<A<dynamic>>>>>> target5 = fsource;
-//                                    ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<Never>> target6 = fsource;
-//                      ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<Never>>> target7 = fsource;
-//                         ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<Never>>>>> target8 = fsource;
-//                               ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<A<Never>>>>>> target9 = fsource;
-//                                  ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<Null>> targe10 = fsource;
-//                      ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<Null>>> target11 = fsource;
-//                         ^^^^^^^
+main() {
+  A? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
@@ -121,6 +65,5 @@ void test(A source) {
 //^
 // [analyzer] unspecified
 // [cfe] unspecified
-}
 
-main() {}
+}
diff --git a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t03.dart b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t03.dart
index 86d7cc4187..89a51b83fe 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t03.dart
@@ -44,6 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for [typedef G<X> =
  * X Function(X)], [class A<X extends G<A<X, Y>>, Y extends X>]
+ *
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
@@ -52,47 +56,10 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<X, Y>>, Y extends X> {}
 
-test(A source) {
-  var fsource = toF(source);
-  F<A<G<A<dynamic, dynamic>>, dynamic>> target = fsource;
 
-  F<A<dynamic, dynamic>> target1 = fsource;
-//                                 ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<dynamic>, dynamic>> target2 = fsource;
-//                                    ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<dynamic>, dynamic>>, dynamic>> target3 = fsource;
-//                                                   ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, Never>>, Never>> target4 = fsource;
-//                                          ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<Never, Never>> target5 = fsource;
-//                             ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<Never>, Never>> target6 = fsource;
-//                                ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, Never>>, Never>> target7 = fsource;
-//                                          ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<dynamic, Never>>, Never>> target8 = fsource;
-//                                            ^^^^^^^
+main() {
+  A? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
@@ -100,6 +67,5 @@ test(A source) {
 //^
 // [analyzer] unspecified
 // [cfe] unspecified
-}
 
-main() {}
+}
diff --git a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t07.dart b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t07.dart
index a430a01c9d..994eb897e0 100644
--- a/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t07.dart
+++ b/LanguageFeatures/Instantiate-to-bound/class/static/class_typedef_l2_t07.dart
@@ -44,7 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiation to bounds works OK for [typedef G<X> =
  * X Function(X)], [class A<X extends G<A<Y, X>>, Y extends G<A<X, Y>>>]
- * @Issue 41963, 41964
+ *
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
@@ -53,83 +56,16 @@ import "../../../../Utils/expect.dart";
 typedef G<X> = X Function(X);
 class A<X extends G<A<Y, X>>, Y extends G<A<X, Y>>> {}
 
-void test(A source) {
-  var fsource = toF(source);
-  F<A<G<A<dynamic, dynamic>>, G<A<dynamic, dynamic>>>> target = fsource;
-
-  F<A<dynamic, G<A<dynamic, dynamic>>>> target1 = fsource;
-//                                                ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<dynamic>, G<A<dynamic, dynamic>>>> target2 = fsource;
-//                                                   ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<G<dynamic>, dynamic>>, G<A<dynamic, dynamic>>>> target3 = fsource;
-//                                                                  ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<dynamic, dynamic>>, dynamic>> target4 = fsource;
-//                                                ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<dynamic, dynamic>>, G<dynamic>>> target5 = fsource;
-//                                                   ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, Never>>, G<A<Never, Never>>>> target6 = fsource;
-//                                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<dynamic, G<A<Never, Never>>>> target7 = fsource;
-//                                            ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<dynamic>, G<A<Never, Never>>>> target8 = fsource;
-//                                               ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-  F<A<G<A<G<Never>, Never>>, G<A<Never, Never>>>> target9 = fsource;
-//                                                          ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, Never>>, Never>> target10 = fsource;
-//                                           ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, Never>>, G<Never>>> target11 = fsource;
-//                                              ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Null, Null>>, G<A<Null, Null>>>> target12 = fsource;
-//                                                    ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
 
-  F<A<G<A<dynamic, Never>>, G<A<dynamic, Never>>>> target13 = fsource;
-//                                                            ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<A<G<A<Never, dynamic>>, G<A<Never, dynamic>>>> target14 = fsource;
-//                                                            ^^^^^^^
+main() {
+  A? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
-}
 
-main() {
   A();
 //^
 // [analyzer] unspecified
 // [cfe] unspecified
+
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t03.dart b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t03.dart
index 2bd70c3c92..33f519c348 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t03.dart
@@ -44,6 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiate-to-bounds works correctly for
  * [typedef A<X> = X Function(X); typedef G<X extends A<X>> = X Function()]
+ *
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +56,8 @@ import "../../../../Utils/expect.dart";
 typedef A<X> = X Function(X);
 typedef G<X extends A<X>> = X Function();
 
+typedef expected = dynamic Function(dynamic) Function();
+
 main() {
-  Expect.equals(
-      typeOf<G<A<dynamic>>>(),
-      typeOf<G>()
-  );
+  Expect.equals(expected, G);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t07.dart b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t07.dart
index a25f5589d8..180bb06656 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t07.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t07.dart
@@ -44,6 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiate-to-bounds works correctly for
  * [typedef A<X> = X Function(X); typedef G<X extends A<X>> = X Function()]
+ *
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +56,8 @@ import "../../../../Utils/expect.dart";
 typedef A<X> = X Function(X);
 typedef G<X extends A<X>> = void Function(X);
 
+typedef expected = void Function(dynamic Function(dynamic));
+
 main() {
-  Expect.equals(
-      typeOf<G<A<dynamic>>>(),
-      typeOf<G>()
-  );
+  Expect.equals(expected, G);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t11.dart b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t11.dart
index 78bf4799f6..0e77b8b382 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t11.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/dynamic/typedef_typedef_l1_t11.dart
@@ -44,6 +44,10 @@
  *   [<U1,m ..., Uk,m>].
  * @description Checks that instantiate-to-bounds works correctly for
  * [typedef A<X> = X Function(X); typedef G<X extends A<X>> = X Function(X)]
+ *
+ * @Issue 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
@@ -52,9 +56,8 @@ import "../../../../Utils/expect.dart";
 typedef A<X> = X Function(X);
 typedef G<X extends A<X>> = X Function(X);
 
+typedef expected = dynamic Function(dynamic) Function(dynamic Function(dynamic));
+
 main() {
-  Expect.equals(
-      typeOf<G<A<dynamic>>>(),
-      typeOf<G>()
-  );
+  Expect.equals(expected, G);
 }
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t01.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t01.dart
index 878e22cb70..0a9c0e3275 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t01.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t01.dart
@@ -45,48 +45,20 @@
  * @description Checks that instantiate-to-bounds works correctly for [typedef]
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>>  = X
  * Function(Y)]
- * @Issue 34689, 34699, 41963, 41964
+ *
+ * @Issue 34689, 34699, 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
 
-import "../../../../Utils/expect.dart";
-
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = X Function(Y);
 
-test(G source) {
-  var fsource = toF(source);
-
-  F<G<A<dynamic>, A<Never>>> target = fsource;
-
-  F<G<A<dynamic>, A<dynamic>>> target1 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Never>,   A<dynamic>>> target2 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Never>,   A<Never>>>   target3 = fsource;
-//                                       ^^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  F<G<A<dynamic>, A<Null>>>    target4 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,    A<dynamic>>> target5 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,   A<Null>>>     target6 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-}
+}
\ No newline at end of file
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t02.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t02.dart
index b68518b57b..43a49b9306 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t02.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t02.dart
@@ -46,49 +46,18 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> = Y
  * Function(X)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
+ *
  * @author iarkh@unipro.ru
  */
 
-import "../../../../Utils/expect.dart";
-
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = Y Function(X);
 
-test(G source) {
-  var fsource = toF(source);
-
-  F<G<A<Never>, A<dynamic>>> target = fsource;
-
-  F<G<A<dynamic>, A<dynamic>>> target1 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<dynamic>, A<Never>>>   target2 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Never>,   A<Never>>>   target3 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<dynamic>, A<Null>>>    target4 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,    A<dynamic>>> target5 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,   A<Null>>>     target6 = fsource;
-//                                       ^^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 }
-
-main() {}
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t03.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t03.dart
index 953485f402..370b256236 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t03.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t03.dart
@@ -46,50 +46,19 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> = X
  * Function(X, Y)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
 
-import "../../../../Utils/expect.dart";
-
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = X Function(X, Y);
 
-test(G source) {
-  var fsource = toF(source);
-
-  F<G<A<dynamic>, A<Never>>> target = fsource;
-
-  F<G<A<dynamic>, A<dynamic>>> target1 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Never>,   A<dynamic>>> target2 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Never>,   A<Never>>>   target3 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<dynamic>, A<Null>>>    target4 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,    A<dynamic>>> target5 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,   A<Null>>>     target6 = fsource;
-//                                       ^^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
-}
 
-main() {}
+}
\ No newline at end of file
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t04.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t04.dart
index d27dd7623c..b8eddf03b9 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t04.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t04.dart
@@ -46,50 +46,18 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> = Y
  * Function(X, Y)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
 
-import "../../../../Utils/expect.dart";
-
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = Y Function(X, Y);
 
-test(G source) {
-  var fsource = toF(source);
-
-  F<G<A<Never>, A<dynamic>>> target = fsource;
-
-  F<G<A<dynamic>, A<dynamic>>> target1 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<dynamic>, A<Never>>>   target2 = fsource;
-//                                       ^^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
-
-  F<G<A<Never>,   A<Never>>>   target3 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<dynamic>, A<Null>>>    target4 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,    A<dynamic>>> target5 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  F<G<A<Null>,   A<Null>>>     target6 = fsource;
-//                                       ^^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-}
-
-main() {}
+}
\ No newline at end of file
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t10.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t10.dart
index 98f66ed934..b3e8de60f7 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t10.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t10.dart
@@ -46,7 +46,8 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> =
  * void Function<X1 extends X>(Y)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
@@ -54,45 +55,10 @@
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = void Function<X1 extends X>(Y);
 
-test(G source) {
-  void Function<X extends A<dynamic>>(Never) target1 = source;
-
-  void Function<X extends A<dynamic>>(A<dynamic>) target2 = source;
-//                                                          ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<dynamic>) target3 = source;
-//                                                        ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<Never>) target4 = source;
-//                                                      ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<dynamic>>(A<Never>) target5 = source;
-
-  void Function<X extends A<dynamic>>(dynamic) target6 = source;
-//                                                       ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<dynamic>>(Null) target7 = source;
-//                                                    ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends dynamic>(Never) target8 = source;
-//                                                  ^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  void Function<X extends Never>(Never) target9 = source;
-//                                                ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
 }
-
-main() {}
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t11.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t11.dart
index 5d8ae0da0d..fb8742e4b9 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t11.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t11.dart
@@ -46,7 +46,8 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> =
  * void Function<X1 extends X>(X, Y)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
@@ -54,46 +55,10 @@
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = void Function<X1 extends X>(X, Y);
 
-test(G source) {
-  void Function<X extends A<dynamic>>(A<dynamic>, A<Never>) target1 = source;
-
-  void Function<X extends A<dynamic>>(A<Never>, A<Never>) target2 = source;
-
-  void Function<X extends A<dynamic>>(A<Never>, A<dynamic>) target3 = source;
-//                                                                    ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<dynamic>>(A<Null>, A<Null>) target4 = source;
-//                                                                ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<dynamic>>(A<dynamic>, A<Null>) target5 = source;
-//                                                                   ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<dynamic>, A<Never>) target6 = source;
-//                                                                  ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<Never>, A<Never>) target7 = source;
-//                                                                ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<Never>, A<dynamic>) target8 = source;
-//                                                                  ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Null>>(A<Null>, A<Null>) target9 = source;
-//                                                             ^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
 }
-
-main() {}
diff --git a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t12.dart b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t12.dart
index bc435cec65..18a9422a36 100644
--- a/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t12.dart
+++ b/LanguageFeatures/Instantiate-to-bound/typedef/static/typedef_l2_01_t12.dart
@@ -46,7 +46,8 @@
  * with two related parameters: [typedef G<X extends A<X>, Y extends A<Y>> =
  * void Function<Y1 extends Y>(X)]
  *
- * @Issue 41963, 41964
+ * @Issue 41963, 41964, 44786
+ * @Issue dart-lang/language#1133
  *
  * @author iarkh@unipro.ru
  */
@@ -54,28 +55,10 @@
 class A<X> {}
 typedef G<X extends A<X>, Y extends A<Y>> = void Function<Y1 extends Y>(X);
 
-test(G source) {
-  void Function<X extends A<dynamic>>(A<Never>) target1 = source;
-
-  void Function<X extends A<dynamic>>(A<dynamic>) target2 = source;
-//                                                          ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<dynamic>) target3 = source;
-//                                                        ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  void Function<X extends A<Never>>(A<Never>) target4 = source;
-//                                                      ^^^^^^
+main() {
+  G? source;
+//   ^^^^^^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  void Function<X extends A<dynamic>>(A<Null>) target5 = source;
-//                                                       ^^^^^^
-// [analyzer] unspecified
-// [cfe] unspecified
 }
-
-main() {}