The AUTO command provides AUTOmatic line numbering. The forms of the command are:
AUTO
Provides automatic line numbering from line 100, and increments the line numbering in steps of 10.
AUTO int
Provides automatic line numbering from line "int" and increments the line numbers in steps of 10.
AUTO int1,int2
Provides automatic line numbering from line int1 and increments the line numbers in steps of int2.
To exit from line numbering, simply press <CR> on a line that contains a line number only.