anchor.diff:      interface IControl with
           member x.IsInvalid = needsRedraw
           member x.Invalidate() =
  -            if not x.IsDisposed && not renderContiuously then
  +            if not x.IsDisposed && not renderContinuously then
                   if not needsRedraw then
                       needsRedraw <- true
                       x.Invalidate()
   
           member x.Paint() =
  -            if not x.IsDisposed && not renderContiuously then
  +            if not x.IsDisposed && not renderContinuously then
                   use g = x.CreateGraphics()
                   use e = new PaintEventArgs(g, x.ClientRectangle)
                   x.InvokePaint(x, e)
  
positive.code: 
                      needsRedraw <- false
  
              if renderContiuously then
                  x.Invalidate()
  
      override x.OnPaint(e) =
  
negative.code:         base.OnHandleCreated(e)
          loaded <- true
          base.MakeCurrent()
           
      member x.Render() = 
          if loaded then
  