Ordinal: Difference between revisions
ZFC not only setting of pure sets. There are also theories with urelements →Von Neumann definition
(Created page with "In set theory, the '''ordinal numbers''' or '''ordinals''' are an extension of the natural numbers that describe the order types of well-ordered sets. A set \( S \) is '''well-ordered''' if each non-empty \( T \subseteq S \) has a least element. ==Von Neumann definition== The Von Neumann definition of ordinals defines ordinals as objects in ZFC. Each ordinal \( \alpha \) is defined as the set of all ordinals less than \( \alpha \).") |
(ZFC not only setting of pure sets. There are also theories with urelements →Von Neumann definition) |
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==Von Neumann definition==
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