Consider the following BNF: P:: = I D Y | I Y D | D I Y | D Y I | Y I D | Y D I I:: = " j" | " s" D:: = "9" | "21" Y:: = "0" | "4" How many nonterminal symbols are in the grammar? How many terminal symbols are in the grammar? Write two strings that are valid according to the BNF. For each of your two strings, give two valid mutants of the string. For each of your two strings, give two invalid mutants of the string. Consider the following BNF: P:: = I D Y | I Y D | D I Y | D Y I | Y I D | Y D I I:: = " j" | " s" D:: = "9" | "21" Y:: = "0" | "4" How many nonterminal symbols are in the grammar? How many terminal symbols are in the grammar? Write two strings that are valid according to the BNF. For each of your two strings, give two valid mutants of the string. For each of your two strings, give two invalid mutants of the string