Power Set

$\textbf{PowerSet} \; \mathcal{A} := \{\; X : X \subseteq \mathcal{A} \; \}$

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$A \in \textbf{Set}$

$\textbf{AtMost} \; A \; X \; Y := \textbf{Includes} \; X \; Y$

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$X \in \textbf{PowerSet} \; A$

$Y \in \textbf{PowerSet} \; A$