While hacking on a reference implementation to go with my work-in-progress paper, I found several bugs in the paper. Mostly embarrassing sign errors, but some off-by-one too.
I also accidentally fixed one algorithm: arbitrarily setting `sgn(0) = 1` instead of `sgn(0) = 0` makes it succeed in more cases (less risk of a singular matrix).
But now I'm considering deleting 3/4 of a page of vagueness about some advanced techniques and replacing with a fuller treatment of the basics: as it is now, you need to know already how to render escape time fractals for my first page to make any sense. Running very tight to the 8-page hard limit...
I might be able to shrink some of the images to 2/3 page instead of 1 whole page, but whether the page breaks will still be good is another issue.