So imagine there's this machine, this machine makes blue and red toys it makes them every day after day. But sometimes this machine makes purple toys, and someone says: 'oh that's a blue toy' or 'oh that's a red toy', so these toys get put with different colours. The red toys get annoyed as the purple toy isn't red and same with the blue. But what if the machine was more complex than that? What if the machine also produced purple toys? The days go by and the machine makes a green toy..