Arsonide: good tutorial but the expressions are wrong: the return value from expressions is ignored. You need to write PieExp like this:
Hehe, can you tell I got confused there? I thought I'd read something about expressions being broken, and I noticed the format changed - at least in the text object, between AC and E, and I couldn't figure out from the text object's expression how it was tied with it's "function".
In a moment I will update the file with your section so there's not more confusion.