Practice Questions

Generate the grammar which accepts the strings which contains the alphabets {a,b}, Where every string

1. starts with 'a'

2. starts and ends with 'a'

3. starts and ends with the same symbol

4. contains atleast two a's

5. fourth symbol from right end is always a

6. length of the string is excatlly 3

7. length of the string is atleast 3

8. length of the string is less than or equal to 3

9. length of the string is congruent to 2 mod 3 ( ie the length of the string should be 'n' when divided by 3 the remainder is 2)

10. a^mb^n, where m + n is even

11. a^mb^n, where m + n is odd

12. a^mb^n, where m not equal to n, m,n >=1

Complete the following crossword puzzle with the concepts that you had studied in your first module