Thanks for the feedback! I was using Codewars to help learn Haskell so I'm not surprised my solution isn't great. Is | b = x valid or do you have another suggestion. Thanks again.

I don't see how with 1 iteration the rule goes from [1] to [1, 1, 1]. I understand that since 1 is next to both borders of the list that we add in 0 to both sides of the 1 which gives us [0, 1, 0], but how do we then get [1, 1, 1] from that? Do we change all cells under consideration to the value in the new cell row? That is, since was have [0, 1, 0] and the rule says 1, both left neighbor, current cell, and right neighbor all become one? The way its worded it sounds like only the current cell changes, which in the case of [0, 1, 0] its already a one so we should just stay [0, 1, 0] not become [1, 1, 1].

This is so elegant it made me feel bad about my solution. Nice work.