(Full context for those who are encountering this)

"These are live-TeXed notes for the courses I took/am taking at Harvard. Typing up my notes with a computer is mostly inspired by this site (which is also a good resource). The purpose of writing up these notes is primarily to use as a reference for myself, and I advise great caution to those trying to learn actual math from them. Brackets indicate that you must be extra cautious when consulting them. If you find anything wrong (mathematically wrong claims or even typos) please notify me by email." https://dongryulkim.wordpress.com/notes/course_notes/