## 1.1 Sample sets

Today we begin our new category of blogs, and they are about probability theory. To begin with, I have to say that the knownledge in these blogs are elementary, while, that just means they are simple and basic but not unimportant. However, these concepts in the following blogs are foundations of the whole probability theory.

The first bolg contains basic concepts of “Set Theory”, and the probability theory is built on them.