anchor.diff:  open System
   open System.IO
   open System.Xml
  -
   
   /// The Framework version.
   type FrameworkVersionType =
  
positive.code:                             { DllName = lib.Name.Replace(lib.Extension, "")
                                Path = relativePath
                                Condition = FramworkCondition.DetectFromPath relativePath } ]
              |> Seq.groupBy (fun info -> info.DllName)
  
          for _,libs in installInfos do
              let libs = libs |> Seq.toArray
              for lib in libs do
                  let installIt,condition =
                     if libs.Length = 1 then true,None else
                      match lib.Condition.FrameworkVersion with
                      | Unknown -> false,None 
                      | Framework fw -> true,Some(sprintf "$(TargetFrameworkVersion) == '%s'" fw)
                      | All -> true,None
  
                      
                  if installIt then                        
                      { DLLName = lib.DllName
                        HintPath = Some(lib.Path.Replace("/", "\\"))
                        Private = true
                        Condition = condition
                        Node = None }
                      |> this.AddReference
  
          if Utils.normalizeXml this.Document <> this.OriginalText then
              this.Document.Save(this.FileName)
  
negative.code:     Path : string
      Condition : FramworkCondition
  }
  
  /// Contains methods to read and manipulate project files.
  type ProjectFile = 
      { FileName: string
  