Аннотация
We state the following results: the family of all infinite computably enumerable sets has no computable numbering; the family of all infinite Π11 sets has no Π11 -computable numbering; the family of all infinite Σ21 sets has no Σ21 -computable numbering. For k > 2, the existence of a Σk1 -computable numbering for the family of all infinite Σk1 sets leads to the inconsistency of ZF.
Язык оригинала | английский |
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Страницы (с-по) | 224-231 |
Число страниц | 8 |
Журнал | Algebra and Logic |
Том | 58 |
Номер выпуска | 3 |
DOI | |
Состояние | Опубликовано - 1 июл 2019 |