Freund, Anton (2024)
A note on ordinal exponentiation and derivatives of normal functions.
In: Mathematical Logic Quarterly, 2020, 66 (3)
doi: 10.26083/tuprints-00016165
Article, Secondary publication, Publisher's Version
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Item Type: | Article |
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Type of entry: | Secondary publication |
Title: | A note on ordinal exponentiation and derivatives of normal functions |
Language: | English |
Date: | 26 January 2024 |
Place of Publication: | Darmstadt |
Year of primary publication: | 2020 |
Place of primary publication: | Weinheim |
Publisher: | Wiley-VCH |
Journal or Publication Title: | Mathematical Logic Quarterly |
Volume of the journal: | 66 |
Issue Number: | 3 |
DOI: | 10.26083/tuprints-00016165 |
Corresponding Links: | |
Origin: | Secondary publication DeepGreen |
Abstract: | Michael Rathjen and the present author have shown that Π11‐bar induction is equivalent to (a suitable formalization of) the statement that every normal function has a derivative, provably in ACA0. In this note we show that the base theory can be weakened to RCA0. Our argument makes crucial use of a normal function f with f(α)≤1+α² and f′(α)=ωωα. We shall also exhibit a normal function g with g(α)≤1+α·2 and g′(α)=ω1+α. |
Status: | Publisher's Version |
URN: | urn:nbn:de:tuda-tuprints-161654 |
Classification DDC: | 500 Science and mathematics > 510 Mathematics |
Divisions: | 04 Department of Mathematics > Logic |
Date Deposited: | 26 Jan 2024 13:45 |
Last Modified: | 27 Feb 2024 14:00 |
SWORD Depositor: | Deep Green |
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/16165 |
PPN: | 51584649X |
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