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In computability theory, computational complexity theory and proof theory, the slow-growing hierarchy is an ordinal-indexed family of slowly increasing functions ''g''α: N → N (where N is the set of natural numbers, ). It contrasts with the fast-growing hierarchy. == Definition == Let μ be a large countable ordinal such that a fundamental sequence is assigned to every limit ordinal less than μ. The slow-growing hierarchy of functions ''g''α: N → N, for α < μ, is then defined as follows: * * * for limit ordinal α. Here α() denotes the ''n''th element of the fundamental sequence assigned to the limit ordinal α. The article on the Fast-growing hierarchy describes a standardized choice for fundamental sequence for all α < ε0. 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「Slow-growing hierarchy」の詳細全文を読む スポンサード リンク
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