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Topic: Regular Language Proof Help
Replies: 1   Last Post: Sep 30, 2013 9:07 PM

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Posts: 5
Registered: 1/30/13
Regular Language Proof Help
Posted: Sep 30, 2013 5:28 PM
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The question is: Is L' a regular language?

L' = {a^(n+2) b^(n-2) : n >= 2, n ? Z}

Here is my proof, but I am not sure it is correct:

y = a^k
x = a^q
z = a^((p+2)-q-k) b^(p-2)

xyyz = a^(q) a^(k) a^(k) a^((p+2)-q-k) b^(p-2)
= a^(k(p+2) b^(p-2) ? L'
Contradiction, L' is not regular.

Is this right?

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