I am Toby Bartels.
If you came to this page by following my name at the bottom of an article, don't assume that I wrote that article! Go back and check the article's History to see who wrote it before you send me email about it. Even if I did write it, it's better if you make a comment right on the page, using a query block. (But if you understand that and still want to send me email, then that's OK too.)
My main interests here are the foundations of mathematics, including constructive mathematics and how to formalise higher category theory internally. I have a liking for centipede mathematics, which I sometimes take too far, but usually it has applications somewhere. I also have an aptitude for negative thinking; my favourite mathematical object is the empty set. Along these lines, I advocate learning order theory before category theory, just as one learns category theory before higher category theory; see category theory vs order theory.
The regulars here may be especially interested in my PhD dissertation, Higher Gauge Theory I: 2-Bundles.
I also have my own personal web here, although not much is on it.