Tsing Ch’a Sessions 清茶会

To promote interdisciplinary interaction between different faculty members and students on the campus, a weekly meeting has been organized by our postdoc Yinlin Guan since September 2020, called Tsing Ch’a Sessions (清茶会). Its slogan “know thyself and let others know you better.”

■Schedule for 2022-2023 Autumn Semester

2022 Sep 22Zhenkun Hu 胡振坤 (Tsinghua University)
2022 Sep 29Qingyu He 何清瑜 (Tsinghua University)
2022 Oct 06Fengxiang Cheng 成凤祥 (Tsinghua University)
2022 Oct 13Mingliang Chu 储明亮 (Tsinghua University)
2022 Oct 20Qian Chen 陈谦 (Tsinghua University)
2022 Oct 27 Yuqi Liu 刘雨琦 (Tsinghua University)
2022 Nov 03Kun Xing 邢锟 (Anyang Normal University)
2022 Nov 10Tianwei Zhang 张天玮 (Technical University of Vienna)
2022 Nov 20Xiaoxin Jing景晓鑫 (Capital Normal University)
2022 Nov 24Yinlin Guan 管银霖 (Tsinghua University), Xiaoxuan Fu 付小轩 (China University of Political science and Law)
2022 Dec 01Jialiang Yan 闫佳亮 (Tsinghua University)
2022 Dec 08Yiyan Wang 王奕岩 (Tsinghua University)
2022 Dec 15Lei Li 李磊 (Tsinghua University)
2022 Dec 22Penghao Du 杜鹏昊 (Tsinghua University)
2022 Dec 29Xuan Li 李旋 (Tsinghua University)

■Current Sessions

2022 Dec 01 14:00-15:30 Jialiang Yan 闫佳亮 (Tsinghua University): Knowing and Believing an Epistemic Possibility

What does it mean to know or believe that something might be the case? In this presentation, we address the issue focusing on the epistemic possibility expressed by English might when embedded under the propositional attitude verbs know and believe. We present some puzzles to highlight the challenges arising from such know-might and believe-might sentences. We propose a framework to solve the puzzles, in which epistemic might is defined as quantifying over the epistemic possibilities in an information state, and belief is formalized in term of a plausibility ordering. In contrast to the classical epistemic logic, the factivity of knowledge is treated as a presupposition rather than being solely dependent on the reflexivity of the accessibility relation. All analyses are implemented in a team-based modal logic BSEL, an epistemic variant of Aloni’s (2022) BSML.

This is a joint work with Maria Aloni.

2022 Nov 20 14:00-15:30 Yinlin Guan 管银霖 (Tsinghua University), Xiaoxuan Fu 付小轩 (China University of Political science and Law): The Paradox of the Dao in the Laozi

The Laozi starts with “the dao that can be spoken of is not the constant dao”. It arises a paradox where the Laozi expresses the ineffability of the dao, but also depicts what the dao is in the text. In this presentation, we argue that the paradox of the dao is a kind of Russell’s paradox. We attempt to solve the paradox of the dao by means of solutions of Russell’s paradox and see if it would further solve the interpretive issues raised by the paradox of the dao

2022 Nov 20 14:00-15:30 Xiaoxin Jing 景晓鑫 (Capital Normal University): Dynamic Epistemic Logic for Multi-agent Abstract Argumentation

Argumentation has become a major research area in Artificial Intelligence over the last two decades. Abstract argumentation is an elegant way to tackle reasoning problems in the presence of conflicting information. The seminal paper by Dung defines an argumentation framework as a digraph whose nodes are abstract entities called arguments, and edges are attacks representing the conflict between these arguments. This presentation aims to introduce a dynamic epistemic logic for multi-agent abstract argumentation.

2022 Nov 10 19:00-20:30 Tianwei Zhang 张天玮 (Technical University of Vienna): Bisimulations over Parity Formulas

This talk is an investigation into how to define the notion of bisimulation over parity formulas. We provide and argue for a list of criteria against which we could judge how good such a definition is. In general, a notion of bisimulation should be sound, closed under union and composition, easily decidable and as close to being complete as possible. It should also guarantee the existence of a largest bisimulation, namely the bisimilarity relation. Particular to the situation with parity formulas, a good bisimulation should also have a ’relative flavor’ in its handling of the priority condition. We propose four definitions of bisimulations over parity formulas and evaluate each of them according to those criteria. We especially argue for one of the four definitions to be the best by far, since it satisfies all qualitative criteria and lies in a relatively good position onthe ’spectrum of completeness’. We also provide an adequate bisimilarity game for this notion of bisimulation which makes it easier to work with the notion.

2022 Nov 03 14:00-15:30 Kun Xing 邢锟 (Anyang Normal University): A Formal Solution to the Symbol Grounding Problem in Natural Language Understanding

Natural Language Understanding (NLU) is a crucial problem in Artificial Intelligence (AI), and the symbolism approach to this problem lies in Formal Semantics. However, traditional theories in Formal Semantics all encounter the symbol grounding problem which prevents them successfully applying to NLU or AI. This presentation, which is based on the first part of the reporter’s doctoral dissertation, aims to give a formal solution to this problem so that one could develop a formal semantic theory more applicable to NLU and AI.

2022 Oct 27 14:00-15:30 Yuqi Liu 刘雨琦 (Tsinghua University): A Formal Analysis of the Why-question of Action

This presentation aims to provide a formal interpretation of the why-question of action, based on a preference logic scenario. Many conceptions in natural language are incorporated, including presuppositions, sentence topics, discourse topics, etc. Compared to the other wh-questions, the why-question is unique in that it requires more satisfying answers. This analysis also provides a process for producing satisfactory answers.

2022 Oct 20 14:00-15:30 Qian Chen 陈谦 (Tsinghua University): Tabularity and Post-Completeness in Tense Logic

This presentation is based on the paper ‘Tabularity and Post-Completeness in Tense Logic’. A new characterization of tabularity in tense logic is established, namely, a tense logic L is tabular if and only if  tabTn ∈ L for some n≥1 . Two characterization theorems for the Post-completeness in tabular tense logics are given. Furthermore, a characterization of the Post-completeness in the lattice of all tense logics is established. Post numbers of some tense logics are shown.

2022 Oct 13 14:00-15:30 Mingliang Chu 储明亮 (Tsinghua University): 以简单类型λ演算看奥卡姆的升降原则

对于升降原则提出的目的,当代学者各执一词。T.K. Scott(1966)认为Ockham的升降原则是量词命题的句法规则的集合,是唯名论量词理论。另一些学者,如G. Priest & S. Read(1977,1980),则认为应该从现代真之理论的视角看,下降(上升)形式是原始句的真之条件。除此之外,P. V. Spade(1988)给出了一种更激进的看法,认为升降原则的提出是无目的性的。而本人认为,奥卡姆提出升降原则某种程度上是对于自然语言中涉及限定词单调推理的一种洞见。这一想法源自于Thomas F . Icard、Lawrence S. Moss和William Tune关于简单类型λ演算的最新成果,即通过将序关系引入简单类型λ演算来分析自然语言中的单调推理。

2022 Oct 06 14:00-15:30 Fengxiang Cheng 成凤祥 (Tsinghua University): A Definition of Conventions by Correlated Equilibrium

In Convention (1968), David Lewis makes the epistemic assumption that the agents have common knowledge of the convention to which they are parties, in the account of conventions, which is based on coordination problems. This became one of the most fecund but controversial developments he put forth in, that is, the study of the relation between common knowledge and social conventions. In my presentation, I will focus on how to define convention by correlated equilibrium according to Peter Vanderschraaf(1995,1998). It generalizes previous game-theoretic definitions of Lewis and can be used to characterize partial conflict situations. Examples and formal definitions will be given to show how this more extensive account of convention can be applied to some game problems as well as norms of justice.

2022 Sep 29 14:00-15:30 Qingyu He 何清瑜 (Tsinghua University): From Quantity to Quality: A Logic for Combining Causality and Belief

Causal Bayesian network plays an important role in artificial intelligence, probability theory and many other fields. In some sense, we can view the scenarios we observed as a causal Bayesian network. Unlike traditional quantitative representation,in this paper, we propose a qualitative representation of causal Bayesian to explore belief revision under Bayesian network. To formalize this idea, we construct a causal plausibility model by combining the plausibility model and the causal model. We develop a logic based on this model and explore properties of the logic. (co-work with Kaibo Xie and Fenrong Liu)

2022 Sep 22 14:00-15:30 Zhenkun Hu 胡振坤 (Tsinghua University): 瓦格纳连锁平行模式(IPS)c部分的不同语法表现及其对《荀子》论证研究的启示


■Past Sessions

Click HERE to check the past sessions.