Agreed, it's a very good overview of the language. In case the author is here, I think there is some confusion in the section about indenting:

> When a token starts on the same line as a token on an earlier line, gluon implicitly adds inserts a block expression

I think this means that lines where tokens start on the same column are part of an implicitly inserted block. The comment on the code snippet is similarly confusing (and seems to have missed a refactor from `id` to `add1`).

Hope that is helpful! Looks like a really nice language.