Special Section: Computability Theory and the Foundation of Mathematics
Models of the Weak König Lemma
2017 年 25 巻 p. 25-34
詳細
2017 年 25 巻 p. 25-34
This paper surveys the model-theoretic aspects of two topics initiated by Kazuyuki Tanaka related to the Weak König Lemma: self-embedding, and conservativity for sentences of the form ∀X ∃!Y θ(X,Y), where θ(X,Y) is an arithmetical formula. It includes a few recent developments and proof sketches.
