Let $\mathcal{A}$ be an D221: Alphabet such that

(i)	$\mathcal{A}^*$ is the D937: Set of strings over $\mathcal{A}$

A D11: Set $\mathcal{L}$ is a language over $\mathcal{A}$ if and only if \begin{equation} \mathcal{L} \subseteq \mathcal{A}^* \end{equation}