title: How is it possible that the language a^n b^2n is regular if and only if it was finite such that 100 => n <= 0?
body: <p>how is it possible that the language a^n b^2n is regular if and only if it was finite such that 100 => n &lt;= 0?</p>
  
  <p>I know that a language in such a form of ( a^n b^n ) when n=>0 is not regular, since we need a temporary memory to keep track of the number of a's and b's, and I know every <em>finite</em> language is regular, but I do not understand what make a finite language in a similar form regular? how can we proof it? I need some clue, besides being able to get its equivalent regular expression, I want some more detailed explanation..</p>
  
  <p>Thanx</p>