title: Regular Languages and Concatenation
body: <p>Regular languages are closed under concatenation - this is demonstrable by having the accepting state(s) of one language with an epsilon transition to the start state of the next language.</p>
  
  <p>If we consider the language L = {a^n | n >=0}, this language is regular (it is simply a*). If we concatenate it with another language L = {b^n | n >=0}, which is also regular, we end up with a^nb^n, but we obviously know this isn't regular. </p>
  
  <p>Where am I going wrong with my logic here? </p>