prove {a^n^3 | n >= 0} is not a cfg

1) assume it is with pumping length p
2) S=wv^ixy^iz = a^p^3
3) vy = a^k 1 <= k <= p

is this correct? does anyone have an idea about what's next? thanks

4/3/2006 9:28:33 PM

haha, pumping lemmas. good luck! the only thing i hated more was Turing machines

4/3/2006 11:43:13 PM

i've forgotten every single thing I ever learned in this class

4/4/2006 3:06:43 AM