Partial fix for #491. Some of the mentioned issues fixed
diff --git a/LanguageFeatures/nnbd/static_errors_A04_t05.dart b/LanguageFeatures/nnbd/static_errors_A04_t05.dart
index 28b0c33..54ec37a 100644
--- a/LanguageFeatures/nnbd/static_errors_A04_t05.dart
+++ b/LanguageFeatures/nnbd/static_errors_A04_t05.dart
@@ -10,8 +10,8 @@
  * or an initializer list entry, unless the variable or field is marked with the
  * 'late' modifier.
  *
- * @description Check that it is a compile-time error if a static variable
- * with potentially non-nullable type has no initializer expression and not
+ * @description Check that it is no compile-time error if a static variable
+ * with potentially non-nullable type has no initializer expression but
  * marked with the 'late' modifier
  * @author sgrekhov@unipro.ru
  */
@@ -20,8 +20,8 @@
 class A {}
 
 class C {
-  static A a;         //# 01: compile-time error
-  static String s;    //# 02: compile-time error
+  static late A a;
+  static late String s;
 }
 
 main() {
diff --git a/LanguageFeatures/nnbd/static_errors_A07_t01.dart b/LanguageFeatures/nnbd/static_errors_A07_t01.dart
index ebaafbd..852d177 100644
--- a/LanguageFeatures/nnbd/static_errors_A07_t01.dart
+++ b/LanguageFeatures/nnbd/static_errors_A07_t01.dart
@@ -15,23 +15,23 @@
 // SharedOptions=--enable-experiment=non-nullable
 
 class A {
-  static void test1(var x, [A a]) {}          //# 01: compile-time error
+  static void test1(var v, [A a]) {}          //# 01: compile-time error
 
-  static void test2(var x, {A a}) {}          //# 02: compile-time error
+  static void test2(var v, {A a}) {}          //# 02: compile-time error
 }
 
 class C<X extends A?> {
   X x;
   C(this.x);
 
-  void test1<X extends A?>(var x, [X x]) {}   //# 03: compile-time error
+  void test1<X extends A?>(var v, [X x]) {}   //# 03: compile-time error
 
-  void test2<X extends A?>(var x, {X x}) {}   //# 04: compile-time error
+  void test2<X extends A?>(var v, {X x}) {}   //# 04: compile-time error
 }
 
-void test1<X extends A?>(var x, [X x]) {}     //# 05: compile-time error
+void test1<X extends A?>(var v, [X x]) {}     //# 05: compile-time error
 
-void test2<X extends A?>(var x, {X x}) {}     //# 06: compile-time error
+void test2<X extends A?>(var v, {X x}) {}     //# 06: compile-time error
 
 main() {
   A? a = new A();
diff --git a/LanguageFeatures/nnbd/static_errors_A07_t02.dart b/LanguageFeatures/nnbd/static_errors_A07_t02.dart
index 4aa5379..630f377 100644
--- a/LanguageFeatures/nnbd/static_errors_A07_t02.dart
+++ b/LanguageFeatures/nnbd/static_errors_A07_t02.dart
@@ -32,23 +32,23 @@
   X x;
   C(this.x);
 
-  void test1<X extends AAlias>(var x, [X x]) {}
+  void test1<X extends AAlias>(var v, [X x]) {}
 //                                        ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  void test2<X extends AAlias>(var x, {X x}) {}
+  void test2<X extends AAlias>(var v, {X x}) {}
 //                                        ^
 // [analyzer] unspecified
 // [cfe] unspecified
 }
 
-void test1<X extends AAlias>(var x, [X x]) {}
+void test1<X extends AAlias>(var v, [X x]) {}
 //                                  ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-void test2<X extends AAlias>(var x, {X x}) {}
+void test2<X extends AAlias>(var v, {X x}) {}
 //                                      ^
 // [analyzer] unspecified
 // [cfe] unspecified
diff --git a/LanguageFeatures/nnbd/static_errors_A07_t03.dart b/LanguageFeatures/nnbd/static_errors_A07_t03.dart
index dcb7e9f..831ae6b 100644
--- a/LanguageFeatures/nnbd/static_errors_A07_t03.dart
+++ b/LanguageFeatures/nnbd/static_errors_A07_t03.dart
@@ -19,23 +19,23 @@
   X x;
   C(this.x);
 
-  void test1<X extends A?>(var x, [X x]) {}
+  void test1<X extends A?>(var v, [X x]) {}
 //                                    ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  void test2<X extends A?>(var x, {X x}) {}
+  void test2<X extends A?>(var v, {X x}) {}
 //                                    ^
 // [analyzer] unspecified
 // [cfe] unspecified
 }
 
-void test1<X extends A?>(var x, [X x]) {}
+void test1<X extends A?>(var v, [X x]) {}
 //                                  ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-void test2<X extends A?>(var x, {X x}) {}
+void test2<X extends A?>(var v, {X x}) {}
 //                                  ^
 // [analyzer] unspecified
 // [cfe] unspecified
diff --git a/LanguageFeatures/nnbd/static_errors_A07_t04.dart b/LanguageFeatures/nnbd/static_errors_A07_t04.dart
index 267829d..735f5ba 100644
--- a/LanguageFeatures/nnbd/static_errors_A07_t04.dart
+++ b/LanguageFeatures/nnbd/static_errors_A07_t04.dart
@@ -21,23 +21,23 @@
   X x;
   C(this.x);
 
-  void test1<X extends AAlias>(var x, [X x]) {}
+  void test1<X extends AAlias>(var v, [X x]) {}
 //                                        ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  void test2<X extends AAlias>(var x, {X x}) {}
+  void test2<X extends AAlias>(var v, {X x}) {}
 //                                        ^
 // [analyzer] unspecified
 // [cfe] unspecified
 }
 
-void test1<X extends AAlias>(var x, [X x]) {}
+void test1<X extends AAlias>(var v, [X x]) {}
 //                                      ^
 // [analyzer] unspecified
 // [cfe] unspecified
 
-void test2<X extends AAlias>(var x, {X x}) {}
+void test2<X extends AAlias>(var v, {X x}) {}
 //                                      ^
 // [analyzer] unspecified
 // [cfe] unspecified
diff --git a/LanguageFeatures/nnbd/static_errors_A09_t01.dart b/LanguageFeatures/nnbd/static_errors_A09_t01.dart
index 6f8e238..71f8535 100644
--- a/LanguageFeatures/nnbd/static_errors_A09_t01.dart
+++ b/LanguageFeatures/nnbd/static_errors_A09_t01.dart
@@ -20,15 +20,27 @@
 
 void test3({required int x}) {}
 
-Function test4 = ({required int x}) {};
-
 typedef void Foo({required int x});
 
 main() {
-  C.test1();                        //# 01: compile-time error
-  C().test2();                      //# 02: compile-time error
-  test3();                          //# 03: compile-time error
-  test4();                          //# 04: compile-time error
+  C.test1();
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  C().test2();
+//    ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    test3();
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
   Foo foo = ({required int x}) {};
-  foo();                            //# 05: compile-time error
+    foo();
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A09_t02.dart b/LanguageFeatures/nnbd/static_errors_A09_t02.dart
index ef8b61b..1aa68c9 100644
--- a/LanguageFeatures/nnbd/static_errors_A09_t02.dart
+++ b/LanguageFeatures/nnbd/static_errors_A09_t02.dart
@@ -20,15 +20,26 @@
 
 void test3({required int x, String y}) {}
 
-Function test4 = ({required int x, String y}) {};
-
 typedef void Foo({required int x, String y});
 
 main() {
-  C.test1(y: "");                             //# 01: compile-time error
-  C().test2(y: "");                           //# 02: compile-time error
-  test3(y: "");                               //# 03: compile-time error
-  test4(y: "");                               //# 04: compile-time error
+  C.test1(y: "");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  C().test2(y: "");
+//    ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    test3(y: "");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
   Foo foo = ({required int x, String y}) {};
-  foo(y: "");                                 //# 05: compile-time error
+    foo(y: "");
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A09_t03.dart b/LanguageFeatures/nnbd/static_errors_A09_t03.dart
index f6cf268..29aa4c2 100644
--- a/LanguageFeatures/nnbd/static_errors_A09_t03.dart
+++ b/LanguageFeatures/nnbd/static_errors_A09_t03.dart
@@ -20,22 +20,47 @@
 
 void test3({required int x, String y, required String z}) {}
 
-Function test4 = ({required int x, String y, required String z}) {};
-
 typedef void Foo({required int x, String y, required String z});
 
 main() {
   Foo foo = ({required int x, String y, required String z}) {};
 
-  C.test1(x: 3, y: "");           //# 01: compile-time error
-  C().test2(x: 1, y: "");         //# 02: compile-time error
-  test3(x: 4, y: "");             //# 03: compile-time error
-  test4(x: 1, y: "");             //# 04: compile-time error
-  foo(x: 5, y: "");               //# 05: compile-time error
+  C.test1(x: 3, y: "");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
 
-  C.test1(z: "No", y: "woman");   //# 06: compile-time error
-  C().test2(z: "no", y: "cry");   //# 07: compile-time error
-  test3(z: "No", y: "woman");     //# 08: compile-time error
-  test4(z: "no", y: "cry");       //# 09: compile-time error
-  foo(z: "No", y: "woman");       //# 10: compile-time error
+  C().test2(x: 1, y: "");
+//    ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    test3(x: 4, y: "");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    foo(x: 5, y: "");
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  C.test1(z: "No", y: "woman");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  C().test2(z: "no", y: "cry");
+//    ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    test3(z: "No", y: "woman");
+//  ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+    foo(z: "No", y: "woman");
+//  ^^^
+// [analyzer] unspecified
+// [cfe] unspecified
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A09_t04.dart b/LanguageFeatures/nnbd/static_errors_A09_t04.dart
index 164517c..01a137e 100644
--- a/LanguageFeatures/nnbd/static_errors_A09_t04.dart
+++ b/LanguageFeatures/nnbd/static_errors_A09_t04.dart
@@ -26,9 +26,6 @@
 void test3({required A x, String y, required A z}) {}
 void test33({required A? x, String y, required A? z}) {}
 
-Function test4 = ({required A x, String y, required A z}) {};
-Function test44 = ({required A? x, String y, required A? z}) {};
-
 typedef void Foo({required A x, String y, required A z});
 typedef void Foo2({required A? x, String y, required A? z});
 
@@ -67,16 +64,6 @@
 // [analyzer] unspecified
 // [cfe] unspecified
 
-  test4(x: a, y: "");
-//                 ^
-// [analyzer] unspecified
-// [cfe] unspecified
-
-  test44(x: a, y: "");
-//                  ^
-// [analyzer] unspecified
-// [cfe] unspecified
-
   foo(x: a, y: "");
 //               ^
 // [analyzer] unspecified
diff --git a/LanguageFeatures/nnbd/static_errors_A15_t01.dart b/LanguageFeatures/nnbd/static_errors_A15_t01.dart
index 6a79adb..e230a55 100644
--- a/LanguageFeatures/nnbd/static_errors_A15_t01.dart
+++ b/LanguageFeatures/nnbd/static_errors_A15_t01.dart
@@ -15,16 +15,32 @@
 class A {
 }
 
-void test(var x) {
-  if (!(x is Object)) {
-    throw x;
-//        ^
+void test1(dynamic x) {
+  throw x;
+//      ^
 // [analyzer] unspecified
 // [cfe] unspecified
-  }
+}
+void test2(Null x) {
+  throw x;
+//      ^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+void test3(A? x) {
+  throw x;
+//      ^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+void test4<T extends Null>(T x) {
+  throw x;
+//      ^
+// [analyzer] unspecified
+// [cfe] unspecified
 }
 
 main() {
-  A? a = null;
-  test(a);
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A20_t01.dart b/LanguageFeatures/nnbd/static_errors_A20_t01.dart
index c92c9a0..1504162 100644
--- a/LanguageFeatures/nnbd/static_errors_A20_t01.dart
+++ b/LanguageFeatures/nnbd/static_errors_A20_t01.dart
@@ -21,9 +21,9 @@
 main() {
   A a = A();
   C c = C();
-  c?.test();                              //# 01: static type warning
-  c?..test();                             //# 02: static type warning
-  c ?? a;                                 //# 03: static type warning
+  a?.test();                              //# 01: static type warning
+  a?..test();                             //# 02: static type warning
+  a ?? c;                                 //# 03: static type warning
   a ??= c;                                //# 04: static type warning
   List<C> clist = [C(), C()];
   List<A> alist = [A(), C(), ...? clist]; //# 05: static type warning
diff --git a/LanguageFeatures/nnbd/static_errors_A20_t02.dart b/LanguageFeatures/nnbd/static_errors_A20_t02.dart
index f8eeae6..a03d1c4 100644
--- a/LanguageFeatures/nnbd/static_errors_A20_t02.dart
+++ b/LanguageFeatures/nnbd/static_errors_A20_t02.dart
@@ -19,19 +19,19 @@
 class C extends A {}
 
 main() {
-  A a = A();
-  C? c = C();
-  c?.test();
-  c?..test();
-  c ?? a;
+  A? a = A();
+  C c = C();
+  a?.test();
+  a?..test();
+  a ?? c;
   a ??= c;
   List<C>? clist = [C(), C()];
   List<A> alist = [A(), C(), ...? clist];
 
-  c = null;
-  c?.test();
-  c?..test();
-  c ?? a;
+  a = null;
+  a?.test();
+  a?..test();
+  a ?? c;
   a ??= c;
   clist = null;
   alist = [A(), C(), ...? clist];
diff --git a/LanguageFeatures/nnbd/static_errors_A20_t03.dart b/LanguageFeatures/nnbd/static_errors_A20_t03.dart
index e4e840d..c20cea2 100644
--- a/LanguageFeatures/nnbd/static_errors_A20_t03.dart
+++ b/LanguageFeatures/nnbd/static_errors_A20_t03.dart
@@ -18,14 +18,15 @@
 
 class C extends A {}
 
+typedef AAlias = A;
 typedef CAlias = C;
 
 main() {
-  A a = A();
+  AAlias a = A();
   CAlias c = C();
-  c?.test();                                //# 01: static type warning
-  c?..test();                               //# 02: static type warning
-  c ?? a;                                   //# 03: static type warning
+  a?.test();                                //# 01: static type warning
+  a?..test();                               //# 02: static type warning
+  a ?? c;                                   //# 03: static type warning
   a ??= c;                                  //# 04: static type warning
   List<CAlias?> clist = [C(), C(), null];   //# 05: static type warning
   List<A> alist = [A(), C(), ...? clist];   //# 06: static type warning
diff --git a/LanguageFeatures/nnbd/static_errors_A20_t04.dart b/LanguageFeatures/nnbd/static_errors_A20_t04.dart
index 4d15d84..382c6f6 100644
--- a/LanguageFeatures/nnbd/static_errors_A20_t04.dart
+++ b/LanguageFeatures/nnbd/static_errors_A20_t04.dart
@@ -19,7 +19,7 @@
   a?.foo();                                 //# 01: static type warning
   a?..foo();                                //# 02: static type warning
   a ?? new Object();                        //# 03: static type warning
-  a ??= new Object();                       //# 04: static type warning
+  a ??= new A();                            //# 04: static type warning
   List<A> list = [A()];
   List<A> alist = [A(), A(), ...? list];    //# 05: static type warning
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A21_t01.dart b/LanguageFeatures/nnbd/static_errors_A21_t01.dart
index d7cd24c..eb1832b 100644
--- a/LanguageFeatures/nnbd/static_errors_A21_t01.dart
+++ b/LanguageFeatures/nnbd/static_errors_A21_t01.dart
@@ -19,6 +19,6 @@
 // SharedOptions=--enable-experiment=non-nullable
 
 main() {
-  var v = null;
+  Null v = null;
   v = null;
 }
diff --git a/LanguageFeatures/nnbd/static_errors_A21_t03.dart b/LanguageFeatures/nnbd/static_errors_A21_t03.dart
index 7f00a09..8148d13 100644
--- a/LanguageFeatures/nnbd/static_errors_A21_t03.dart
+++ b/LanguageFeatures/nnbd/static_errors_A21_t03.dart
@@ -13,8 +13,8 @@
  *  dynamic
  *  void
  *
- * @description Check that null can be assigned to nullable type. Test S* for
- * some S where S is nullable. Test type aliases
+ * @description Check that null can be assigned to nullable type. Test S? for
+ * some S. Test type aliases
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable,nonfunction-type-aliases
diff --git a/LanguageFeatures/nnbd/syntax_A01_t04.dart b/LanguageFeatures/nnbd/syntax_A01_t04.dart
index 644fbcb..9ed1d42 100644
--- a/LanguageFeatures/nnbd/syntax_A01_t04.dart
+++ b/LanguageFeatures/nnbd/syntax_A01_t04.dart
@@ -4,8 +4,8 @@
  * BSD-style license that can be found in the LICENSE file.
  */
 /**
- * @assertion A new primitive type Never. This type is denoted by the built-in
- * type declaration Never declared in dart:core.
+ * @assertion The grammar of types is extended to allow any type to be suffixed
+ * with a ? (e.g. int?) indicating the nullable version of that type.
  *
  * @description Check that any type can be suffixed with a ? indicating the
  * nullable version of that type. Test type aliases
diff --git a/LanguageFeatures/nnbd/syntax_A05_t01.dart b/LanguageFeatures/nnbd/syntax_A05_t01.dart
index 77e1eb9..4141bc3 100644
--- a/LanguageFeatures/nnbd/syntax_A05_t01.dart
+++ b/LanguageFeatures/nnbd/syntax_A05_t01.dart
@@ -10,7 +10,7 @@
  * {int? y, required int z}).
  *
  * @description Check that any named parameter declaration can be prefixed by
- * the 'required' modifier
+ * the 'required' modifier. Test one named required parameter
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
@@ -21,7 +21,6 @@
 class C {
   static String test1({required String x}) => x;
   String test2({required String x}) => x;
-  A test3({covariant required A x}) => x;
   A test4({required covariant A x}) => x;
 }
 
@@ -37,7 +36,6 @@
   A a = new A();
   Expect.equals("Love me tender", C.test1(x: "Love me tender"));
   Expect.equals("love me sweet", C().test2(x: "love me sweet"));
-  Expect.equals(a, C().test3(x: a));
   Expect.equals(a, C().test4(x: a));
   Expect.equals("never let me go", test5(x: "never let me go"));
   Expect.equals("You have made my life complete",
diff --git a/LanguageFeatures/nnbd/syntax_A05_t02.dart b/LanguageFeatures/nnbd/syntax_A05_t02.dart
index 7eceb24..144f468 100644
--- a/LanguageFeatures/nnbd/syntax_A05_t02.dart
+++ b/LanguageFeatures/nnbd/syntax_A05_t02.dart
@@ -10,7 +10,7 @@
  * {int? y, required int z}).
  *
  * @description Check that any named parameter declaration can be prefixed by
- * the 'required' modifier
+ * the 'required' modifier. Test more than one named parameter
  * @author sgrekhov@unipro.ru
  */
 // SharedOptions=--enable-experiment=non-nullable
@@ -21,8 +21,7 @@
 class C {
   static String test1(int x, {required String y, String z}) => y;
   String test2(int x, {required String y, String z}) => y;
-  A test3(int x, {covariant required String y, String z}) => y;
-  A test4(int x, {required covariant String y, String z}) => y;
+  A test4(int x, {required covariant A y, String z}) => y;
 }
 
 String test5(int x, {required String y, String z}) => y;
@@ -37,7 +36,6 @@
   A a = new A();
   Expect.equals("Love me tender", C.test1(3, y: "Love me tender"));
   Expect.equals("love me sweet", C().test2(1, y: "love me sweet", z: ""));
-  Expect.equals(a, C().test3(4, y: a));
   Expect.equals(a, C().test4(1, y: a, z: ""));
   Expect.equals("never let me go", test5(1, y: "never let me go"));
   Expect.equals("You have made my life complete",
diff --git a/LanguageFeatures/nnbd/syntax_A05_t03.dart b/LanguageFeatures/nnbd/syntax_A05_t03.dart
new file mode 100644
index 0000000..6a9feec
--- /dev/null
+++ b/LanguageFeatures/nnbd/syntax_A05_t03.dart
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+ * for details. All rights reserved. Use of this source code is governed by a
+ * BSD-style license that can be found in the LICENSE file.
+ */
+/**
+ * @assertion The modifier required is added as a built-in identifier. The
+ * grammar of function types is extended to allow any named parameter
+ * declaration to be prefixed by the required modifier (e.g. int Function(int,
+ * {int? y, required int z}).
+ *
+ * @description Check that any named parameter declaration can be prefixed by
+ * the 'required' modifier. Test when required named parameter is not the first
+ * one
+ * @author sgrekhov@unipro.ru
+ */
+// SharedOptions=--enable-experiment=non-nullable
+import "../../Utils/expect.dart";
+
+class A {}
+
+class C {
+  static String test1(int x, {String z, required String y}) => y;
+  String test2(int x, {String z, required String y}) => y;
+
+  A test4(int x, {String z, required covariant A y}) => y;
+}
+
+String test5(int x, {String z, required String y}) => y;
+
+typedef String Foo(int x, {String z, required String y});
+
+Foo test6 = (int x, {String z, required String y}) => y;
+
+Function test7 = (int x, {String z, required String y}) => y;
+
+main() {
+  A a = new A();
+  Expect.equals("Love me tender", C.test1(3, y: "Love me tender"));
+  Expect.equals("love me sweet", C().test2(1, y: "love me sweet", z: ""));
+  Expect.equals(a, C().test4(1, y: a, z: ""));
+  Expect.equals("never let me go", test5(1, y: "never let me go"));
+  Expect.equals("You have made my life complete",
+      test6(5, y: "You have made my life complete", z: ""));
+  Expect.equals("and I love you so", test7(9, y: "and I love you so"));
+}
diff --git a/LanguageFeatures/nnbd/syntax_A08_t01.dart b/LanguageFeatures/nnbd/syntax_A08_t01.dart
index e93ed93..73f8433 100644
--- a/LanguageFeatures/nnbd/syntax_A08_t01.dart
+++ b/LanguageFeatures/nnbd/syntax_A08_t01.dart
@@ -29,4 +29,13 @@
   dynamic a2 = false;
   var v2 = { a2 as bool ? - 3 : 3 };
   Expect.setEquals({3}, v2);
+
+  var a3 = 42;
+  var v3 = { a3 is int ? - 3 : 3 };
+  Expect.setEquals({-3}, v3);
+
+  dynamic a4 = 3.14;
+  var v4 = { a4 is int ? - 3 : 3 };
+  Expect.setEquals({3}, v4);
+
 }
diff --git a/LanguageFeatures/nnbd/syntax_A08_t02.dart b/LanguageFeatures/nnbd/syntax_A08_t02.dart
deleted file mode 100644
index 33d6fb4..0000000
--- a/LanguageFeatures/nnbd/syntax_A08_t02.dart
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
- * for details. All rights reserved. Use of this source code is governed by a
- * BSD-style license that can be found in the LICENSE file.
- */
-/**
- * @assertion Conditional expressions inside of braces are ambiguous between
- * sets and maps. That is, { a as bool ? - 3 : 3 } can be parsed as a set
- * literal { (a as bool) ? - 3 : 3 } or as a map literal
- * { (a as bool ?) - 3 : 3 }. Parsers will prefer the former parse over the
- * latter.
- *
- * The same is true for { a is int ? - 3 : 3 }.
- *
- * The same is true for { int ? - 3 : 3 } if we allow this.
- *
- * @description Check that { a is int ? - 3 : 3 } is parsed as
- * { (a is int) ? - 3 : 3 }
- * @author sgrekhov@unipro.ru
- */
-// SharedOptions=--enable-experiment=non-nullable
-import "../../Utils/expect.dart";
-
-main() {
-  var a = 42;
-  var v = { a is int ? - 3 : 3 };
-  Expect.setEquals({-3}, v);
-
-
-  dynamic a2 = 3.14;
-  var v2 = { a2 is int ? - 3 : 3 };
-  Expect.setEquals({3}, v2);
-}