anchor.diff:      with exn -> None
   
     static member IsInteractiveAvailable =
  -    FSharpInteractivePad.Pad |> Option.isSome
  +    match FSharpInteractivePad.Pad with
  +    | Some(pad) -> match pad.Content with
  +                   | :? FSharpInteractivePad as fsipad -> fsipad.IsValidSession
  +                   | _ -> false
  +    | None -> false
   
     static member BringToFront(grabfocus) =
       FSharpInteractivePad.Pad |> Option.iter (fun pad -> pad.BringToFront(grabfocus))
  
positive.code:       view.Child.KeyPressEvent.Add(fun ea ->
          if ea.Event.State &&& ModifierType.ControlMask = ModifierType.ControlMask && ea.Event.Key = Key.period then
            !session |> Option.iter (fun s -> s.Interrupt()))
        activeDoc <- IdeApp.Workbench.ActiveDocumentChanged.Subscribe ensureCorrectDirectory |> Some
  
        x.UpdateFont()   
  
  
negative.code:     let orderedreferences = orderAssemblyReferences.Order references
      ensureCorrectDirectory()
      sendCommand orderedreferences
      
    member x.IsValidSession = !session |> Option.isSome
  
    static member private Pad =
      try let pad = IdeApp.Workbench.GetPad<FSharpInteractivePad>()
  