I have studied Pumping Lemma carefully and have solved many exercises about it but I can't get an idea on how to solve this one: can anyone help me?
Let L = { w#x | x is a substring of w }. Prove that L is not regular.
I have tried setting the Pumping length to |w| and to |x| but I just don't find words that are not in L..
Thx in advance
