I also find it very interesting that the author doesn't indent the code at all.
I have a feeling (hope) that that was unintentional---like the blog formatting is just eating whitespace or something. Also, the first "Arc if" has a missing right parenthesis and uses = for comparison. :)
I was hoping other people would investigate their code! :) My personal arc directory filtered by hand for completeness (I have a lot of half-finished projects lying around), plus some stock Arc stuff I forgot in the last post: