Give a bnf grammar for each of the languages below.

a) the set of all strings consisting of one or more lower case letters.

b) the set of all strings consisting of one or more digits with a period between each and the next. there should be no period before the first nor after the last digit.

c) the set of all strings consisting of the keyword start, followed by zero or more commands with a period after each command, followed by the keyword stop. use the non-terminal for commands, and do not give productions for it.

d) the set of all strings consisting of a left parenthesis followed by a list of one or more lower case letters separated by commas, followed by a right parenthesis. there should be no comma before the first letter nor after the last letter.

Design a class tictactoe that: holds the following information about the game: two-dimensional array (3 by 3), and winner. add additional variables as needed. includes the functions to perform the various operations on objects. for example, function to print the board, getting the move, checking if move is valid, determining if there is a winner after each move. add additional operations as needed. includes constructor(s). write the functions of the class, and write a program that uses the class. the program should declare an object of type tictactoe. the program will create the board and store it in the array. the program will allow two players to play the tic-tac-toe game. after every valid move update the array, check if there is a winner. if there is no winner and no tie, then print the board again to continue.