Function ui::event_loop_alpha

async fn event_loop_alpha<GV, PB2>(
    initial_state: GV::G, 
    pb1: PUCT, 
    pb2: PB2, 
    rx: Receiver<GuiToSimChannel>, 
    tx: GuiEventSender
) where
    PB2: MultiplayerPolicyBuilder<GV::G>,
    GV: GameView,
    GV::G: Game + SingleWinner + Features + Clone, 

AlphaZero event loop, managing the game instance.