Introduction - If you have any usage issues, please Google them yourself
The program can calculate any given grammar of all non-ultimate breaks and the ultimate symbol of the first set, all non-ultimate symbol of the follow set of the select set of all the statements can be derived to guide the ultimate symbol of non-empty set. Given an arbitrary string that the program can determine whether it can accept out. As the empty symbol bad input, an empty symbol used in the program all the available @ said.