Archive For Mathematical Logic ( IF 0.3 ) Pub Date : 2020-02-11 , DOI: 10.1007/s00153-019-00708-4 C. Dimitracopoulos , V. Paschalis
In this paper, we prove results concerning the existence of proper end extensions of arbitrary models of fragments of Peano arithmetic (PA). In particular, we give alternative proofs that concern (a) a result of Clote (Fundam Math 127(2):163–170, 1986); (Fundam Math 158(3):301–302, 1998), on the end extendability of arbitrary models of \(\Sigma _n\)-induction, for \(n{\ge } 2\), and (b) the fact that every model of \(\Sigma _1\)-induction has a proper end extension satisfying \(\Delta _0\)-induction; although this fact was not explicitly stated before, it follows by earlier results of Enayat and Wong (Ann Pure Appl Log 168:1247–1252, 2017) and Wong (Proc Am Math Soc 144:4021–4024, 2016).
中文翻译:
PA片段模型的末端扩展
在本文中,我们证明了有关Peano算法(PA)的任意片段模型的适当末端扩展的存在的结果。特别是,我们给出了与(a)Clote的结果有关的替代证明(Fundam Math 127(2):163-170,1986);(Fundam Math 158(3):301–302,1998),关于\(\ n Sigma_n \)归纳的任意模型对于\(n {\ ge} 2 \)和(b)每个\(\ Sigma _1 \)归纳模型都有一个满足\(\ Delta _0 \)归纳的适当末端扩展;尽管之前没有明确说明这一事实,但随后是Enayat和Wong(Ann Pure Appl Log 168:1247–1252,2017)和Wong(Proc Am Math Soc 144:4021–4024,2016)的早期结果。