5. Define a context- free grammar to generate the set of strings {aⁿ bⁿ | n is zero or a positive integer}.

6. Consider the following grammar:

S ---> abB, A ---> aaBb, B ---> bbAa, A --->

Derive abbbaabba from the grammar rules. Show each step. How many strings can this grammar generate? Draw a syntax tree for your derivation.

7. Cnsider the grammar with the following rules:

S ---> aAB, A ---> bBb, B ---> A | .

Find the FIRST sets of S, A, B.