Teach you how to learn the first set and follow set!!!! Hematemesis collection!! Nanny level explanation!!!

Let's start the compass ！！

Here's about FIRST The definition of "set" is excerpted from the following blog , Because I think the definition of big guy is detailed enough , The original link is below ！
The boss' article is also very powerful , Worship ！！




there mooc The photo is from Xi'an University of Posts and telecommunications mooc Course ---- In the video of the second lecture in Chapter 4 of compilation principles , Thank the teachers of the teaching team for their hard work .
Here's about FOLLOW The definition of set is also very clear .
mooc Link ！





FIRST Set and FOLLOW The construction of sets is an important basic concept in the course of compiling principles , It took me an afternoon to refresh my mind , I just stood on the shoulders of many big men and felt FIRST Set and FOLLOW The threshold of the set , I hope I can help you ！
If you don't understand it correctly , Please correct me. ！