I wonder if they also have a strategy for deleting generate tiles, otherwise the infinite is limited to the size of available memory. I also wonder if with their method can exactly recreate tiles that have been deleted. Or in other words, that they have a method for generating unique seeds for all tiles. The paper does not give much technical details. If the seed has a limited size and there is a method for generating seeds for each 2D coordinate, I wonder if it is possible to make a non-repeating infinite world. I think it is not possible with a limited size seed.