Just a quick bit of business here: I’ve automated the Math Guide Owner membership process. You no longer need to email proof of purchase to me to gain access (everybody at once: YAASSSS!!)—all you need to do is go to this page, scroll to the bottom, and verify your book ownership by answering one randomized question about the book’s content (e.g., what’s the fifth word on page X?). From now on, you’ll be able to get your discount code instantly, instead of having to wait for an email response from me.
Note: If you purchased your book from the PWN store, you already have Math Guide Owner privileges through the account from which you made the purchase.