March 21, 2006

**Printed Name:**________________________________________

"On my honor, as an Aggie, I have neither given nor received unauthorized aid on this academic work. In particular, I certify that I have not received or given any assistance that is contrary to the letter or the spirit of the collaboration guidelines for this assignment."

**Signature:**___________________________________________

- (5 pts)
Use the pumping lemma for context-free languages to prove
that the following language L is not context-free:

L consists of all binary strings whose length is a power of 3.