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Talk:Alpha recursion theory

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What is 'L'

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I'm assuming L_sub_alpha is the alpha-th level of the constructible universe, can someone confirm this and if so, it should be lnked to Constructible_universe Zero sharp (talk) 23:44, 3 June 2008 (UTC)[reply]

Yes, it is, linking C7XWiki (talk) 20:29, 25 April 2021 (UTC)[reply]

"Admissible ordinals are models of Kripke–Platek set theory."

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This is probably supposed to mean either that admissible SETS are models of KP or that for an admissible ordinal, the corresponding L-level is a model of KP? As it stands, it is certainly false. — Preceding unsigned comment added by 79.235.170.206 (talk) 21:00, 12 January 2015 (UTC)[reply]

"An admissible set is closed under functions"

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As it currently reads I think this claim is false, since for any admissible set , if we take some and define , is on but is not closed under (i.e. "" is false, in fact "" is false.) The closest I can find to this in "The fine structure of the constructible hierarchy" is in the proof of lemma 2.13, where it says "but is closed under since is in . So I am not sure that there's a source for this claim. C7XWiki (talk) 07:01, 6 July 2023 (UTC)[reply]