anchor.diff:  [<AutoOpen>]
   module OmniGame =
   
  -    type Gui =
  +    type GuiModel =
           | Splashing
           | Title
           | Credits
   
       type [<NoComparison>] OmniModel =
  -        | Gui of Gui
  +        | Gui of GuiModel
           | Gameplay of FieldModel
   
       type [<NoComparison>] OmniMessage =
  -        | UpdateModel
  +        | Update
  +        | UpdateModel of OmniModel
           | UpdateFieldModel of FieldModel
           | UpdateBattleModel of BattleModel
  -        | SetModel of OmniModel
   
       type [<NoComparison>] OmniCommand =
           | Show of Screen
  
positive.code:             base.Register (game, world)
  
          override this.Channel (_, _) =
              [Simulants.TitleExit.ClickEvent => [cmd Exit]
               Simulants.TitlePlay.ClickEvent => [msg (SetModel (Gameplay FieldModel.empty))]
               Simulants.TitleCredits.ClickEvent => [msg (SetModel (Gui Credits))]
               Simulants.CreditsBack.ClickEvent => [msg (SetModel (Gui Title))]
               Simulants.FieldBack.ClickEvent => [msg (SetModel (Gui Title))]
               Simulants.Game.UpdateEvent => [msg UpdateModel]
               Simulants.Field.FieldModel.ChangeEvent =|> fun evt -> [msg (UpdateFieldModel (evt.Data.Value :?> FieldModel))]
               Simulants.Battle.BattleModel.ChangeEvent =|> fun evt -> [msg (UpdateBattleModel (evt.Data.Value :?> BattleModel))]]
  
          override this.Message (model, message, _, world) =
              match message with
              | UpdateModel ->
                  match model with
                  | Gui Splashing -> just model
                  | Gui Title -> withCmd model (Show Simulants.Title)
                  | Gui Credits -> withCmd model (Show Simulants.Credits)
                  | Gameplay field ->
                      match field.BattleOpt with
                      | Some battle ->
  
negative.code:                             else withCmd model (Show Simulants.Field)
                          | _ -> withCmd model (Show Simulants.Battle)
                      | None -> withCmd model (Show Simulants.Field)
  
          override this.Command (_, command, _, world) =
              let world =
  