∈, the element is a member of the set, ∉, the element is not a member of a set, ∅, the set has no members (empty set), n(A), the number of elements in set A, ℰ, the universal set, A', the set of elements not in A (complement), AnB, elements that belong to both set A and set B (intersection), AuB, elements that belong to set A or Set B or both A and B (union).

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