Lab1.
A nice test script
formatted code base
add some code,but this is not the last copyright
the lexer is completed and the next time will write the code of the parse
the lsxer was completed
this is the first push and there is not changing nothing
just a little
complete the lab2 of mengning
modify a bug
add two function and modify some buys
exercise is complete, there is may some buys
the Lab1 is solution
merge
the Exercise 2 is compelte, and I will continue to finish the Exercise 3
in order to fix a bug
change something
the Lab2 is complete except exercise 9
Merge branch 'Lab2SolutionFan' into Lab3

Conflicts:
	src/ast/Fac.java