Give a counterexample to show that the following construction fails to prove that the class of context-free languages is closed under star. Let $A$ be a $\text{CFL}$ that is generated by the $\text{CFG}$ $G = (V, \Sigma, R, S).$ Add the new rule $S\rightarrow SS$ and call the resulting grammar $G'.$This grammar is supposed to generate $A^{*}.$
