So I've experimented with removing the size stuff, and while it's no big deal to remove and doesn't really affect the rest of funkis that much, it does impact the API of lazy sequences. Where the `next` method used to be oblivious to counting the number of times it's been called, so as not to be infinite, it now has to keep track of that. It's a bit of a nuisance, and takes away some of the elegance of writing sequences like that. However, I think it's still possible to regain some of that elegance simply by introducing a new function called `limit` or some such, which will limit the number of times a function can be called, and once that limit is reached will always return `nil`. This abstracts the counting away from the `next` function and so it can go back to truly just calculating the next value.