Note that this is not shuffle but perfect shuffle, defined as follows:Let $w = a_{1}a_{2} \ldots a_{n}$ and $x = b_{1}b_{2} \ldots b_{n}$ be two strings of the same length. Then the perfect shuffle of $w$ and $x$ is defined as $a_{1}b_{1}a_{2}b_{2} \ldots a_{n}b_{n}$.So the question is: are context free languages closed under perfect shuffle?
Is Context Free Language closed under perfect shuffle?
formal languages;context free;closure properties