皆様,
東北大学の竹田です.
以下の通りセミナーを開催いたしますのでご案内いたします.
https://sites.google.com/view/sendai-logic/
日時:5月24日(金)15:00〜
場所:東北大学理学研究科合同A棟801号室 (zoom配信あり)
講演者:鈴木悠大 (国立沖縄高専)
題目 On the Pi^1_2, Sigma^1_2 and Boole(Pi^1_2) sentences provable from Pi^1_1-CA_0
概要 In [1], we introduced some characterizations of the set of Pi^1_2 sentences provable from Pi^1_1-CA_0 and a hierarchy dividing it. For a detailed study of the properties of this hierarchy, it was important to focus on the statements of the form [every coded beta-model satisfies sigma] for some specific sentences sigma.
In this talk, we summarize a part of [1]. Then we give a characterization of the set of Sigma^1_2 or Boole(Pi^1_2) sentences provable from Pi^1_1-CA_0 by statements of the form [every coded beta-model satisfies sigma]. Here, Boole(Pi^1_2) is the class of formulas generated by disjunction, conjunction and negation starting from Pi^1_2.
This is joint work with J. Aguilera and K. Yokoyama.
[1] Suzuki, Y., & Yokoyama, K. (2024). On the $\Pi^ 1_2 $ consequences of $\Pi^ 1_1 $-$\mathsf {CA} _0$. arXiv preprint arXiv:2402.07136.
オンライン参加を希望される方は竹田(yuto.takeda.t8(a)dc.tohoku.ac.xn--jp)-u63baam6azav5czbevh0gij9rvoja5sb4j6736j2rvgn34dhb1b
どうぞよろしくお願いいたします.
竹田 侑人
yuto.takeda.t8(a)dc.tohoku.ac.jp