[zen_of_prog]

If the pattern matches the top three tiles, then the tile below is defined by the bottom tile in the rules. This is done top down, row by row for each 3-tile section of a row. You're totally right though.

[DeepYogurt]

Just so I understand; some tile on row n in column m would depend on three tiles in row n-1 where those three would be in columns m-1, m, and m+1?

How does that work for edges and for the first tile? Also is the pattern just implicitly started with a single tile?

Thanks for the explanation :)

[concreteblock]

Yes, that's correct.

There are no edges, it's an infinite grid. You start with 1 black cell and all the other cells are white.

Because the triple-white configuration does not produce a black cell, you can compute up the any finite time step with finite computational power.

(Actually, later in the article he talks about finite grids with periodic boundary conditions. That means that, if you're on the edge, you 'wrap around' to the other side of the grid).

[DeepYogurt]

Gotcha. Thanks for taking the time :)