9.28

9.27

9.26

9.25

## 分析学简明教程 A Brief Tutorial on Analysis

<s>我 TM 又开一坑。[捂脸]</s>

## THE BOOK reading log

REMARK Due to the author 的随性而至，本文中英夹杂。

## Ch. 17

We claim any 2 arbitrary sets are in equal size or cardinality, iif there exists a bijection from M onto N.

We denote sets with the same size of $\mathbb{N}$ countable.