Let $A_n$ be a sequence of sets having the same cardinality $k$ (possibly uncountable, and may not be equal to the cardinality of the continuum). Also assume they are disjoint. How could I show that $\cup_n A_n$ has cardinality $k$?
2026-03-29 14:07:06.1774793226
Countable Union of sets of the same cardinality
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