$+$ program that reads a description of a context free grammar, then, depending on

the command line argument passed to the program, performs one of the following tasks $($see Section $6\mathrm{.}3$ for more details on how

to run the program with command line arguments$)$:

$1.$ print the list of terminals followed by the list of non$-$terminals in the order in which they appear in the grammar,

$2.$ calculate nullable non$-$terminals,

$3.$ calculate FIRST sets,

$4.$ calculate FOLLOW sets $,$