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In set theory, a supertransitive class is a transitive class 〔Any element of a transitive set must also be its subset. See Definition 7.1 of 〕 which includes as a subset the power set of each of its elements. Formally, let ''A'' be a transitive class. Then ''A'' is supertransitive if and only if :〔See Definition 9.8 of 〕 Here ''P''(''x'') denotes the power set of ''x''.〔''P''(''x'') must be a set by axiom of power set, since each element ''x'' of a class ''A'' must be a set (Theorem 4.6 in Takeuti's text above).〕 ==See also== * Transitive set * Rank (set theory) 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Supertransitive class」の詳細全文を読む スポンサード リンク
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