Hints for HW 10
---------------

(1) See the TM state diagrams on pages 144-145 in Sipser.
This problem is not intended to be tricky.  

We strongly urge you to also include a brief explanation
of how your TM works.  You won't get full credit if the
graders can't figure out how it works in a reasonable
amount of time.

(2) This question is not especially hard.   It's labelled bonus
because we know that not everyone will have time to absorb the
context-free pumping lemma.

See example 2.37 in Sipser.  This proof can be done in a similar
way.  Context-free pumping lemma proofs almost always contain several
cases, each covering one way that a substring (yzw) of length
<= p could be positioned within your much longer pumping string s.