```clafer
TrafficLightSystem
    Lamps
        Red
            xor shape
                ball
                square
        Yellow
            xor shape
                ball
                diamond
        Green
            shape
                ball
    allBalls ?
        [ Red.shape.ball && Yellow.shape.ball ]
    xor orientation
        vertical
            [ allBalls ]
        horizontal
            [ Red.shape.square && Yellow.shape.diamond ]
    
```

```{.clafer .config}
```

> Back to [country specific features](country specific features#conclusion-of-part-i)