tests/cases/compiler/typeParameterDiamond4.ts(8,13): error TS2322: Type 'Top | T | U' is not assignable to type 'Top'.
  'Top' could be instantiated with an arbitrary type which could be unrelated to 'Top | T | U'.
    Type 'T' is not assignable to type 'Top'.
      'Top' could be instantiated with an arbitrary type which could be unrelated to 'T'.
tests/cases/compiler/typeParameterDiamond4.ts(10,13): error TS2322: Type 'Bottom' is not assignable to type 'Top'.
  'Top' could be instantiated with an arbitrary type which could be unrelated to 'Bottom'.
    Type 'Top | T | U' is not assignable to type 'Top'.
      'Top' could be instantiated with an arbitrary type which could be unrelated to 'Top | T | U'.
        Type 'T' is not assignable to type 'Top'.
          'Top' could be instantiated with an arbitrary type which could be unrelated to 'T'.


==== tests/cases/compiler/typeParameterDiamond4.ts (2 errors) ====
    function diamondTop<Top>() {
        function diamondMiddle<T, U>() {
            function diamondBottom<Bottom extends Top | T | U>() {
                var top: Top;
                var middle: Top | T | U;
                var bottom: Bottom;
    
                top = middle;
                ~~~
!!! error TS2322: Type 'Top | T | U' is not assignable to type 'Top'.
!!! error TS2322:   'Top' could be instantiated with an arbitrary type which could be unrelated to 'Top | T | U'.
!!! error TS2322:     Type 'T' is not assignable to type 'Top'.
!!! error TS2322:       'Top' could be instantiated with an arbitrary type which could be unrelated to 'T'.
                middle = bottom;
                top = bottom;
                ~~~
!!! error TS2322: Type 'Bottom' is not assignable to type 'Top'.
!!! error TS2322:   'Top' could be instantiated with an arbitrary type which could be unrelated to 'Bottom'.
!!! error TS2322:     Type 'Top | T | U' is not assignable to type 'Top'.
!!! error TS2322:       'Top' could be instantiated with an arbitrary type which could be unrelated to 'Top | T | U'.
!!! error TS2322:         Type 'T' is not assignable to type 'Top'.
!!! error TS2322:           'Top' could be instantiated with an arbitrary type which could be unrelated to 'T'.
            }
        }
    }