WKL$\mathsf{WKL}下实值连续函数的编码$

IF 0.4 4区 数学 Q4 LOGIC Mathematical Logic Quarterly Pub Date : 2023-07-24 DOI:10.1002/malq.202200031
Tatsuji Kawai
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引用次数: 0

摘要

在构造逆数学的背景下,我们证明了弱König引理(WKL$\mathsf{WKL}$)暗示了每个逐点连续函数f:[0,1]→ R$f:[0,1]\rightarrow\mathbb{R}$是由逆向数学意义上的代码引起的。结合WKL$\mathsf{WKL}$隐含范定理的事实,表明WKL$\mathsf{WKL}$隐含一致连续性定理:每个逐点连续函数f:[0,1]→ R$f:[0,1]\rightarrow\mathbb{R}$具有一致连续模。我们的结果是在Heyting算法中得到的,在所有有限类型中都有无量词选择公理。
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Coding of real-valued continuous functions under WKL $\mathsf {WKL}$

In the context of constructive reverse mathematics, we show that weak Kőnig's lemma ( WKL $\mathsf {WKL}$ ) implies that every pointwise continuous function f : [ 0 , 1 ] R $f : [0,1]\rightarrow \mathbb {R}$ is induced by a code in the sense of reverse mathematics. This, combined with the fact that WKL $\mathsf {WKL}$ implies the Fan theorem, shows that WKL $\mathsf {WKL}$ implies the uniform continuity theorem: every pointwise continuous function f : [ 0 , 1 ] R $f : [0,1]\rightarrow \mathbb {R}$ has a modulus of uniform continuity. Our results are obtained in Heyting arithmetic in all finite types with quantifier-free axiom of choice.

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来源期刊
CiteScore
0.60
自引率
0.00%
发文量
49
审稿时长
>12 weeks
期刊介绍: Mathematical Logic Quarterly publishes original contributions on mathematical logic and foundations of mathematics and related areas, such as general logic, model theory, recursion theory, set theory, proof theory and constructive mathematics, algebraic logic, nonstandard models, and logical aspects of theoretical computer science.
期刊最新文献
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