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arXiv 1602.01822math.LO
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Peano算术的慢可证性和普通可证性

Slow and Ordinary Provability for Peano Arithmetic

Paula Henk, Fedor Pakhomov

摘要:

Peano算术的慢可证性($\mathsf{PA}$)是由S. D.弗里德曼,M。Rathjen和A.魏尔曼他们研究了慢一致性声明$\mathrm{Con}_{\mathsf{s}}$,该声明断言矛盾在$\mathsf{PA}$中不是慢可证明的。他们表明,$\mathsf{PA}+\mathrm{Con}_{\mathsf{s}}$的逻辑强度严格介于$\mathsf{PA}$和$\mathsf{PA}$之间,以及它的普通一致性:$\mathsf{PA}\subsetneq \mathsf{PA}+\mathrm{Con}_{\mathsf{s}}\subsetneq \mathsf{PA}+\mathrm{Con}$。本文进一步研究了$\mathsf{PA}$中的慢可证明性及其与普通可证明性之间的关系。我们研究了慢可证性的三种变体。每一个的相关一致性陈述产生一个理论,该理论在逻辑强度方面严格介于$\mathsf{PA}$和$\mathsf{PA}+\mathrm{Con}$之间。我们研究图灵-费弗曼级数的基础上,这些变种的慢证明。我们表明,对于我们的三个概念,图灵-费弗曼级数达到$\mathsf{PA}+\mathrm{Con}$在不同的步骤,即$\varepsilon_0$,$ω$,和$2$。对于三个慢可证明性谓词中的每一个,我们还确定其与普通$\mathsf{PA}$ -可证明性的联合可证明性逻辑。

英文摘要:

The notion of slow provability for Peano Arithmetic ($\mathsf{PA}$) was introduced by S.D. Friedman, M. Rathjen, and A. Weiermann. They studied the slow consistency statement $\mathrm{Con}_{\mathsf{s}}$ that asserts that a contradiction is not slow provable in $\mathsf{PA}$. They showed that the logical strength of $\mathsf{PA}+\mathrm{Con}_{\mathsf{s}}$ lies strictly between that of $\mathsf{PA}$ and $\mathsf{PA}$ together with its ordinary consistency: $\mathsf{PA}\subsetneq \mathsf{PA}+\mathrm{Con}_{\mathsf{s}}\subsetneq \mathsf{PA}+\mathrm{Con}$. This paper is a further investigation into slow provability and its interplay with ordinary provability in $\mathsf{PA}$. We study three variants of slow provability. The associated consistency statement of each of these yields a theory that lies strictly between $\mathsf{PA}$ and $\mathsf{PA}+\mathrm{Con}$ in terms of logical strength. We investigate Turing-Feferman progressions based on these variants of slow provability. We show that for our three notions, the Turing-Feferman progression reaches $\mathsf{PA}+\mathrm{Con}$ in a different numbers of steps, namely $\varepsilon_0$, $ω$, and $2$. For each of the three slow provability predicates, we also determine its joint provability logic with ordinary $\mathsf{PA}$-provability.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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