Let EQ = {w : number of a's = number of b's } Let EQO = { anbn : n ∈  N} (so its Equal and in Order) Typically we do the following: Prove EQO is not regular by the pumping lemma. Then to show EQ is not regular you say: If EQ was regular than EQ INTERSECT a*b*= EQO is regular, hence EQ is not regular (I know you can also show EQ with the Pumping Lemma but thats not important now.) One can v