anchor.diff:      files |> Seq.map (fun x -> AssemblyId.from x) 
             |> set
   
  -let Install () =
  -    let antho = Configuration.LoadAnthology ()
  -    PaketParsing.UpdateSources antho.NuGets
  +
  +let InstallPackages (nugets : RepositoryUrl list) =
  +    PaketParsing.UpdateSources nugets
   
       let confDir = Env.GetFolder Env.Config
       Exec.Exec "paket.exe" "install" confDir
  
positive.code:                       |> Map.toList
                        |> Seq.map (fun (k, v) -> k)
      allPackages |> Seq.iter GenerateTargetForPackage
  
  let Update () =
      let confDir = Env.GetFolder Env.Config
  
negative.code:     newAntho
  
  let Simplify (antho : Anthology) =
      InstallPackages antho.NuGets
      
      let newAntho = SimplifyAnthology antho
      newAntho
  