+Zorn's Lemma is a powerful result in [Set Theory](/wiki/set_theory), equivalent to the [Axiom of Choice](/wiki/axiom_of_choice). It states that if every chain in a [Partially Ordered Set](/wiki/partially_ordered_set) has an upper bound, then the set contains at least one [Maximal Element](/wiki/maximal_element). This lemma is a crucial tool for proving existence theorems in various branches of mathematics.
+## See also
+- [Axiom of Choice](/wiki/axiom_of_choice)
+- [Well-ordering Theorem](/wiki/well-ordering_theorem)
+- [Partial Order](/wiki/partial_order)
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