anchor.diff:      let xnuspec = XDocument.Load (nuspecFile.FullName)
       let dependencies = GetPackageDependencies xnuspec
   
  -    let whens = GenerateTargetForAllFxVersion package libDir
  +    let whens = GenerateTargetForAllFxVersion libDir
       let imports = GenerateDependencyImport dependencies
       let choose = if whens.Any() then XElement (NsMsBuild + "Choose", whens)
                    else null
  
positive.code:       ("v1.1", ["11"; "net11"])    
        ("v1.0", ["10"]) ] 
  
  let GenerateItemGroup (fxLibs : DirectoryInfo) =
      let pkgDir = WorkspacePackageFolder ()
      seq {
          let dlls = fxLibs.EnumerateFiles("*.dll")
          let exes = fxLibs.EnumerateFiles("*.exes")
          let files = Seq.append dlls exes
          for file in files do
              let assemblyName = Path.GetFileNameWithoutExtension (file.FullName)
              let relativePath = ComputeRelativePath pkgDir file
  
negative.code:                     XElement(NsMsBuild + "Private", "true"))
      }
  
  let GenerateItemGroup (fxLibs : DirectoryInfo) =
      let pkgDir = WorkspacePackageFolder ()
      let dlls = fxLibs.EnumerateFiles("*.dll")
      let exes = fxLibs.EnumerateFiles("*.exes")
      let files = Seq.append dlls exes
      GenerateItemGroupContent pkgDir files
  
  let rec GenerateWhenContent (folders : string list) (fxVersion : string) (fxFolders : DirectoryInfo seq) =
      let matchLibfolder (fx : string) (dir : DirectoryInfo) =
          if fx = "" then true
          else
              let dirNames = dir.Name.Replace("portable-", "").Split('+')
              dirNames |> Seq.contains fx
  
      match folders with
      | [] -> null
      | fxFolder::tail -> let libDir = fxFolders |> Seq.tryFind (matchLibfolder fxFolder)
                          match libDir with
                          | None -> GenerateWhenContent tail fxVersion fxFolders
                          | Some libFolder -> let itemGroup = GenerateItemGroup libFolder
                                              if itemGroup.Any() then
                                                  let condition = sprintf "'$(TargetFrameworkVersion)' == '%s'" fxVersion
                                                  XElement(NsMsBuild + "When",
                                                      XAttribute(NsNone + "Condition", condition),
                                                      XElement(NsMsBuild + "ItemGroup", 
                                                          itemGroup))
                                              else
                                                  null
  
  let GenerateTargetForAllFxVersion (libDir : DirectoryInfo) =
      seq {
          if libDir.Exists then
              let fxFolders = libDir.EnumerateDirectories()
              for (fxName, _) in FxVersion2Folder do
                  let fxWhens = FxVersion2Folder |> Seq.skipWhile (fun (fx, _) -> fx <> fxName)
                                                 |> Seq.map (fun (_, folders) -> GenerateWhenContent folders fxName fxFolders)
                  let fxDefaultWhen = [ [""] ] |> Seq.map (fun folders -> GenerateWhenContent folders fxName [libDir])
                  let fxWhen = Seq.append fxWhens fxDefaultWhen |> Seq.tryFind (fun x -> x <> null)
  
                  match fxWhen with
                  | Some x -> yield x
                  | None -> ()
      }
  
  let GenerateDependencyImport (dependencies : string seq) =
  