anchor.diff:  
       override this.ConvertTo (_, _, source, destType) =
           if destType = typeof<Symbol> then
  -            let box2 = source :?> Box2i
  +            let box2i = source :?> Box2i
               Symbols
  -                ([Number (scstring box2.Position.X, None)
  -                  Number (scstring box2.Position.Y, None)
  -                  Number (scstring box2.Size.X, None)
  -                  Number (scstring box2.Size.Y, None)], None) :> obj
  +                ([Symbols ([Number (scstring box2i.Position.X, None); Number (scstring box2i.Position.Y, None)], None)
  +                  Symbols ([Number (scstring box2i.Size.X, None); Number (scstring box2i.Size.Y, None)], None)], None) :> obj
           elif destType = typeof<Box2i> then source
           else failconv "Invalid Box2iConverter conversion to source." None
   
  
positive.code:         match source with
          | :? Symbol as symbol ->
              match symbol with
              | Symbols ([Number (x, _); Number (y, _); Number (z, _); Number (w, _)], _) ->
                  Box2i (scvalue x, scvalue y, scvalue z, scvalue w) :> obj
              | _ ->
                  failconv "Invalid Box2iConverter conversion from source." (Some symbol)
          | :? Box2i -> source
          | _ -> failconv "Invalid Box2iConverter conversion from source." None
  
  [<AutoOpen>]
  
negative.code:         if destType = typeof<Symbol> then
              let box2 = source :?> Box2
              Symbols
                  ([Symbols ([Number (scstring box2.Position.X, None); Number (scstring box2.Position.Y, None)], None)
                    Symbols ([Number (scstring box2.Size.X, None); Number (scstring box2.Size.Y, None)], None)], None) :> obj
          elif destType = typeof<Box2> then source
          else failconv "Invalid Box2Converter conversion to source." None
  
  