anchor.diff:                  let field = Field.updateMenu (fun menu -> { menu with MenuState = state }) field
                   just field
               
  +            | MenuTechAlly index ->
  +                let field =
  +                    Field.updateMenu (fun menu ->
  +                        let state =
  +                            match menu.MenuState with
  +                            | MenuTech menuTech -> MenuTech { menuTech with TechIndexOpt = Some index }
  +                            | state -> state
  +                        { menu with MenuState = state })
  +                        field
  +                just field
  +            
               | MenuClose ->
                   let field = Field.updateMenu (fun menu -> { menu with MenuState = MenuClosed }) field
                   just field
  
positive.code:                     Content.panel Gen.name
                         [Entity.Position == v2 -448.0f -256.0f; Entity.Elevation == Constants.Field.GuiElevation; Entity.Size == v2 896.0f 512.0f
                          Entity.LabelImage == Assets.Gui.DialogXXLImage]
                         [sidebar (v2 24.0f 420.0f) 1.0f field]
                   
                   // use
                   Content.entityIf field (fun field _ -> Option.isSome field.Menu.MenuUseOpt) $ fun field _ ->
  
negative.code:         | MenuItemUse of int
          | MenuItemCancel
          | MenuTechOpen
          | MenuTechAlly of int
          | MenuClose
          | ShopBuy
          | ShopSell
  