This document last updated 18 June 2025.
I'll list corrections to the main pdf documents here and incorporate them into the main pdf documents from time to time.
2020 14: There are also minimum points at (0,+/-1/sqrt(2)). (Thank you to Angelos Bochoris.)
2023 I 11(d): The second expression should be omitted: it is equivalent to the third expression. (Thank you to Angelos Bochoris and Danylo Kvit.)
)