Summer update
Some notable changes:
- The source code for Yanqi Lake Lectures on Algebra: Part 1 is now available as GitHub and Gitee repositories, and the PDF has been recompiled. As mentioned in the old version, the original source code was accidentally deleted long ago; this version was recovered by AI, and numerous corrections have been made.
- Numerous corrections have been made to Lectures on Algebra.
- A partial draft of Methods of Algebra: Volume 3 is released. Comments are welcome.