anchor.diff:          PatriciaSet.IsProperSuperset (otherSet.Trie, trie)
   
       /// Returns a new IntSet made from the given elements.
  -    static member OfSeq (source : seq<int>) : IntSet =
  +    static member internal OfSeq (source : seq<int>) : IntSet =
           // Preconditions
           checkNonNull "source" source
   
           IntSet (PatriciaSet.OfSeq source)
   
       /// Returns a new IntSet made from the given elements.
  -    static member OfList (source : int list) : IntSet =
  +    static member internal OfList (source : int list) : IntSet =
           // Preconditions
           checkNonNull "source" source
   
  
positive.code:         
          set1.Intersect set2
  
      /// Returns a new set with the elements of the second set removed from the first.
      [<CompiledName("Difference")>]
      let inline difference (set1 : IntSet) (set2 : IntSet) : IntSet =
  
negative.code:         checkNonNull "set2" set2
  
          set1.Intersect set2
          |> retype
  
      /// Computes the intersection of a sequence of sets.
      [<CompiledName("IntersectMany")>]
      let intersectMany (sets : seq<TagSet<'Tag>>) : TagSet<'Tag> =
          // Retype as seq<IntSet>
          let sets : seq<IntSet> = retype sets
  
          // Preconditions checked by the target method.
          IntSet.IntersectMany sets
          |> retype
  
      /// Returns a new set with the elements of the second set removed from the first.
  