anchor.diff:                          let uReader = FSharpValue.PreComputeUnionReader(uci, allMembers)
                           let tupleCtor = FSharpValue.PreComputeTupleConstructor tupleType
                           let tupleReader = FSharpValue.PreComputeTupleReader tupleType
  -                        { CaseInfo = uci ; PayloadType = tupleType ;
  +                        { UnionCaseInfo = uci ; PayloadType = tupleType ;
                               UCtor = tupleReader >> uctor ;
                               UProj = uReader >> tupleCtor }
   
  
positive.code:     abstract Visit<'T when 'T : comparison> : unit -> 'R
  
  type IShapeFSharpSet =
      inherit IShapeCollection
      abstract Accept : IFSharpSetVisitor<'R> -> 'R
  
  type ShapeFSharpSet<'T when 'T : comparison> () =
      inherit TypeShape<Set<'T>> ()
      interface IShapeEnumerable with
          member __.Accept v = v.Visit<'T> ()
  
negative.code:     abstract Visit<'T when 'T : equality> : unit -> 'R
  
  type IShapeHashSet =
      abstract Accept : IHashSetVisitor<'R> -> 'R
  
  type private ShapeHashSet<'T when 'T : equality> () =
      inherit TypeShape<HashSet<'T>> ()
      interface IShapeEnumerable with
          member __.Accept v = v.Visit<'T> ()
  