What you are talking about is Ouyang Guangzhong's mathematical analysis (third edition), that is, Chen's book is very classic, and the following mathematical analysis books are almost all formed on this basis, which is relatively more mature than Chen Jixiu's book, and the following exercises are also good. I recommend reading Chen's Mathematical Analysis (the third edition of Ouyang Guangzhong). This book is also a reference textbook or mathematical analysis for most mathematics majors compiled by East China Normal University!