anchor.diff:      { Graph : Graph
         Bookmark : Anthology.Bookmark }
   with
  -    override this.Equals(other : System.Object) =
  -        System.Object.ReferenceEquals(this, other)
  +    override this.Equals(other : System.Object) = refEquals this other
   
       interface System.IComparable with
           member this.CompareTo(other) = compareTo this other (fun x -> x.Bookmark.Repository)
  
positive.code:     | :? 'T as x -> System.Collections.Generic.Comparer<'U>.Default.Compare(fieldOf this, fieldOf x)
      | _ -> failwith "Can't compare values with different types"
  
  
  [<RequireQualifiedAccess>] 
  type PackageVersion =
  
negative.code: and [<CustomEquality; CustomComparison>] Repository =
      { Graph : Graph
        Repository : Anthology.Repository }
  with
      override this.Equals(other : System.Object) = refEquals this other
  
      interface System.IComparable with
          member this.CompareTo(other) = compareTo this other (fun x -> x.Repository.Name)
  