{"id":9653,"date":"2026-03-11T10:24:01","date_gmt":"2026-03-11T02:24:01","guid":{"rendered":"https:\/\/tsinghualogic.net\/JRC\/?page_id=9653"},"modified":"2026-04-14T11:44:48","modified_gmt":"2026-04-14T03:44:48","slug":"tsing-cha-past-session-from-2025","status":"publish","type":"page","link":"https:\/\/tsinghualogic.net\/JRC\/tsing-cha-past-session-from-2025\/","title":{"rendered":"Tsing Ch&#8217;a Past Session from 2025"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"9653\" class=\"elementor elementor-9653\" data-elementor-settings=\"[]\">\n\t\t\t\t\t\t\t<div class=\"elementor-section-wrap\">\n\t\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-4181bd5 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"4181bd5\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-0226be4\" data-id=\"0226be4\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-e14efc8 elementor-widget elementor-widget-text-editor\" data-id=\"e14efc8\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.5.6 - 28-02-2022 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#818a91;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#818a91;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<h4><strong>Sessions in 2025-2026 Fall Semester<\/strong><\/h4>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-d3e0058 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"d3e0058\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-1c60309\" data-id=\"1c60309\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-5e12848 elementor-widget elementor-widget-text-editor\" data-id=\"5e12848\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<h3>\u00a0<\/h3><p><!-- \/wp:heading --><\/p><p><!-- wp:table {\"className\":\"is-style-stripes\"} --><\/p><figure><table><thead><tr><th data-align=\"left\"><strong>Date<\/strong><\/th><th data-align=\"left\"><strong>Speaker<\/strong><\/th><\/tr><\/thead><tbody><tr><td data-align=\"left\">2025 Nov 6<\/td><td data-align=\"left\">Qian Chen \u9648\u8c26 (Tsinghua University)<\/td><\/tr><tr><td data-align=\"left\">2025 Nov 20<\/td><td data-align=\"left\">Xi Yang \u6768\u66e6 (Tsinghua University) [<a href=\"https:\/\/tsinghualogic.net\/JRC\/logic-reading-program\/\">Logic Reading Program<\/a>]<\/td><\/tr><tr><td data-align=\"left\">2025 Dec 11\u00a0<\/td><td data-align=\"left\">Weijun Yu \u4f59\u4f1f\u4fca (Tsinghua University)<\/td><\/tr><tr><td data-align=\"left\">2025 Dec 12<\/td><td data-align=\"left\">Xi Yang \u6768\u66e6 (Tsinghua University) [<a href=\"https:\/\/tsinghualogic.net\/JRC\/logic-reading-program\/\">Logic Reading Program<\/a>]<\/td><\/tr><tr><td data-align=\"left\">2025 Dec 26<\/td><td data-align=\"left\">Xin Li \u674e\u946b (Tsinghua University) [<a href=\"https:\/\/tsinghualogic.net\/JRC\/logic-reading-program\/\">Logic Reading Program<\/a>]<\/td><\/tr><tr><td data-align=\"left\">2026 Jan 6<\/td><td data-align=\"left\">Xin Li \u674e\u946b (Tsinghua University) [<a href=\"https:\/\/tsinghualogic.net\/JRC\/logic-reading-program\/\">Logic Reading Program<\/a>]<\/td><\/tr><\/tbody><\/table><\/figure>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-94f1d8e elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"94f1d8e\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-bef18b9\" data-id=\"bef18b9\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-fdac666 elementor-widget elementor-widget-toggle\" data-id=\"fdac666\" data-element_type=\"widget\" data-widget_type=\"toggle.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.5.6 - 28-02-2022 *\/\n.elementor-toggle{text-align:left}.elementor-toggle .elementor-tab-title{font-weight:700;line-height:1;margin:0;padding:15px;border-bottom:1px solid #d4d4d4;cursor:pointer;outline:none}.elementor-toggle .elementor-tab-title .elementor-toggle-icon{display:inline-block;width:1em}.elementor-toggle .elementor-tab-title .elementor-toggle-icon svg{-webkit-margin-start:-5px;margin-inline-start:-5px;width:1em;height:1em}.elementor-toggle .elementor-tab-title .elementor-toggle-icon.elementor-toggle-icon-right{float:right;text-align:right}.elementor-toggle .elementor-tab-title .elementor-toggle-icon.elementor-toggle-icon-left{float:left;text-align:left}.elementor-toggle .elementor-tab-title .elementor-toggle-icon .elementor-toggle-icon-closed{display:block}.elementor-toggle .elementor-tab-title .elementor-toggle-icon .elementor-toggle-icon-opened{display:none}.elementor-toggle .elementor-tab-title.elementor-active{border-bottom:none}.elementor-toggle .elementor-tab-title.elementor-active .elementor-toggle-icon-closed{display:none}.elementor-toggle .elementor-tab-title.elementor-active .elementor-toggle-icon-opened{display:block}.elementor-toggle .elementor-tab-content{padding:15px;border-bottom:1px solid #d4d4d4;display:none}@media (max-width:767px){.elementor-toggle .elementor-tab-title{padding:12px}.elementor-toggle .elementor-tab-content{padding:12px 10px}}<\/style>\t\t<div class=\"elementor-toggle\" role=\"tablist\">\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-2651\" class=\"elementor-tab-title\" data-tab=\"1\" role=\"tab\" aria-controls=\"elementor-tab-content-2651\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 Dec 11 15:00-16:30 Weijun Yu (\u4f59\u4f1f\u4fca, Tsinghua University) From Seeing-as to Knowing-as: On Mohist Knowledge and Logic<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-2651\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"1\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-2651\"><p><strong>Abstract:<\/strong><\/p><p>In his\u00a0Philosophical Investigations, Wittgenstein distinguishes between\u00a0seeing\u00a0and\u00a0seeing-as, arguing that in seeing we do not merely receive perceptual input but interpret the object under different aspects. Inspired by this distinction, Michael Beaney develops the notion of\u00a0knowing-as, which differs from\u00a0knowing-that\u00a0and\u00a0knowing-how, concerning the aspects in which something is known.\u00a0Knowing-as\u00a0is structurally ambiguous: the expression \u201cI know X as Y\u201d may mean \u201cI know X-as-Y,\u201d or \u201cI-as-Y know X.\u201d These two structures correspond respectively to aspectual knowledge and perspectival knowledge. In this talk, I will focus on Mohist epistemology and logic to analyze the concept of\u00a0knowing-as. First, I will review Wittgenstein\u2019s distinction of\u00a0seeing\/seeing-as\u00a0and Beaney\u2019s theory of\u00a0knowing-as, comparing with the parallel analogy of\u00a0seeing\u00a0and\u00a0knowing\u00a0in\u00a0Mohist Canon, to establish a bridge between\u00a0seeing-as\u00a0and\u00a0knowing-as. Second, I will discuss the two senses of\u00a0knowing-as\u00a0in Mohist philosophy: I will relate\u00a0knowing-as\u00a0to Mohist concept\u00a0leiqu\u985e\u53d6(\u2018selecting according to kind\u2019) and compare Mohist and Zhuangzian perspectival epistemology. Finally, since\u00a0knowing-as\u00a0is also closely connected to analogical reasoning, which is seen as the central feature of Chinese logic, I will quote Beaney\u2019s logical interpretations of the Happy Fish Dialogue and argue that Mohists have a theory of analogical justification.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-2652\" class=\"elementor-tab-title\" data-tab=\"2\" role=\"tab\" aria-controls=\"elementor-tab-content-2652\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 Nov 6 16:00-17:30 Qian Chen (\u9648\u8c26, Tsinghua University) Degree of Kripke-incompleteness of tense logics<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-2652\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"2\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-2652\"><p>Tense logics are normal bi-modal logics with \u2018future-looking\u2019 and \u2018past-looking\u2019 modalities. The degree of Kripke-incompleteness of a logic L in some lattice C of logics is the cardinality of logics in C which share the same class of Kripke-frames with L. A celebrated result on Kripke-incompleteness is Blok\u2019s dichotomy theorem for the degree of Kripke-incompleteness in the lattice NExt(K) of all normal modal logics: every normal modal logic L is of the degree of Kripke-incompleteness 1 or continuum. In this talk, we focus on the lattice NExt(K4t) of all normal extensions of K4t, where K4t is the tense logic of transitive frames. We show that Blok\u2019s theorem of the degree of Kripke-incompleteness for modal logic K can be extended to K4t.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-1aa8ca5 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"1aa8ca5\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-bf6715f\" data-id=\"bf6715f\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-73189a8 elementor-widget elementor-widget-text-editor\" data-id=\"73189a8\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<h4><strong>Sessions in 2025-2026 Spring Semester<\/strong><\/h4>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-98dcf2f elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"98dcf2f\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-61dff7e\" data-id=\"61dff7e\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-6ecdbfc elementor-widget elementor-widget-toggle\" data-id=\"6ecdbfc\" data-element_type=\"widget\" data-widget_type=\"toggle.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-toggle\" role=\"tablist\">\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1161\" class=\"elementor-tab-title\" data-tab=\"1\" role=\"tab\" aria-controls=\"elementor-tab-content-1161\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 Feb 27 14:00-15:30 Sisi Yang (\u6768\u601d\u601d, Tsinghua University) Axiomatization problem of Temporal STIT Logic<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1161\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"1\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1161\"><p>The integration of temporal reasoning with agency\u2014the formalization of how agents make choices over time\u2014is a foundational area of study in philosophy and logic. Temporal logic and STIT (Seeing to It That) logic have been well-established separately, with complete axiomatizations existing for both systems. Temporal STIT (TSTIT) logic combines temporal operators with STIT operators to model agency over time. While there has been some prior work on the axiomatization of TSTIT logic, existing results are limited to specific classes of STIT frames, leaving the general axiomatization problem open. In this talk, we will focus on the axiomatization of TSTIT logic with temporal operators X, F, and the STIT operator for a single agent, interpreted over discrete time and bundled trees. Specifically, we will explore a transformation method involving bundled trees and Ockhamist frames, which aims at constructing a general STIT frame.<\/p><p>This is a joint work with Zhang Yan.<\/p><section><strong>References:<br \/><\/strong>[Belnap et al.(2001)] Nuel Belnap, Michael Perloff, and Ming Xu. 2001.\u00a0Facing the future: agents and choices in our indeterminist world. Oxford University Press.\u00a0<section>[Ciuni and Zanardo(2010)] Roberto Ciuni and Alberto Zanardo. 2010. Completeness of a branching-time logic with possible choices.\u00a0Studia Logica\u00a096 (2010), 393\u2013420.\u00a0<\/section><section>[Ciuni and Lorini(2018)] Roberto Ciuni and Emiliano Lorini. 2018. Comparing semantics for temporal STIT logic.\u00a0Logique et Analyse\u00a0243 (2018), 299\u2013339.<\/section><\/section><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1162\" class=\"elementor-tab-title\" data-tab=\"2\" role=\"tab\" aria-controls=\"elementor-tab-content-1162\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 March 20 14:00-15:30 Wenfei Ouyang (\u6b27\u9633\u6587\u98de, Tsinghua University) Representation Theorem in Disjunctive Dependence<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1162\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"2\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1162\"><p>Disjunctive dependence is an interesting variant of functional dependency, which is used to express dependency like \u201cx functionally determines y or z\u201d. In this talk, I will discuss representation theorem for disjunctive dependence in dependence models and present some negative and positive results on it.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1163\" class=\"elementor-tab-title\" data-tab=\"3\" role=\"tab\" aria-controls=\"elementor-tab-content-1163\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 April 24 14:00-15:30 Haoxuan Luo (\u7f57\u660a\u8f69, Tsinghua University) An Epistemic Logic for Formalizing Correlations<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1163\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"3\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1163\"><p data-tool=\"mdnice\u7f16\u8f91\u5668\">When faced with complex epistemic-combinatorial situations, agents struggle to formally differentiate between relational patterns, creating gaps in formal models.<\/p><p data-tool=\"mdnice\u7f16\u8f91\u5668\">To address this, we introduce strictly relevant operators and construct an Epistemic Logic based on Possible Knowledge Bases (<em>EL_{PKB}<\/em>). Among these, these new operators require not only the absence of counterexample situations but also every truth cases must exist, ensuring a precise representation.<\/p><p data-tool=\"mdnice\u7f16\u8f91\u5668\">To this end, we introduce a non-Kripke model that incorporates PKBs to define the semantics. In this context, a PKB refers to the knowledge combinations that an agent might possess in a given state. Then we explore the correspondence between PKBs under different definitions and the cognitive properties of agents.<\/p><p data-tool=\"mdnice\u7f16\u8f91\u5668\">In the end, we try to provide sequent calculus for this logic.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1164\" class=\"elementor-tab-title\" data-tab=\"4\" role=\"tab\" aria-controls=\"elementor-tab-content-1164\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 May 8 16:00-17:30 Xin Li (\u674e\u946b, Tsinghua University) An exponential lower bound of proof complexity for substructural logics by R. Jalali<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1164\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"4\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1164\"><p>This is a report of this paper: Jalali, Raheleh. &#8220;Proof complexity of substructural logics.&#8221;\u00a0Annals of Pure and Applied Logic\u00a0172.7 (2<span data-mpa-action-id=\"mab3cvev1epy\">021): 102972.<\/span><\/p><section>One of the most important aims of proof complexity is proving lower bounds on proof size for tautological formulae in various proof systems. Aside from the extensive study of some well-known classical proof systems, recently there have been some investigations into the complexity of proofs in non-classical logics. In R. Jalali (2021), the author investigates the proof complexity of a wide range of substructural systems and concludes that for any proof system P at least as strong as Full Lambek calculus and polynomially simulated by the extended Frege system for some superintuitionistic logic of infinite branching, there is an exponential lower bound on the proof lengths.<\/section><section><span data-mpa-action-id=\"mab3cvev1t1n\">In this talk, I will first present a simple example of resolution system and show how proof complexity system works. Then I will introduce Jalali&#8217;s work: construct hard tautologies to show the existence of an exponential lower bound on the lengths of proofs in proof systems and on the number of proof lines for a wide range of substructural logics.<\/span><\/section><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1165\" class=\"elementor-tab-title\" data-tab=\"5\" role=\"tab\" aria-controls=\"elementor-tab-content-1165\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 May 29 14:00-15:30 Weijun Yu (\u4f59\u4f1f\u4fca, Tsinghua University) Knowledge in early Chinese thought by Donald Sturgeon<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1165\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"5\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1165\"><p><span data-mpa-action-id=\"mav3ib4e5v0\" data-pm-slice=\"0 0 []\">Donald Sturgeon\u2019s Ph.D thesis is an inquiry of the epistemology in early China. In this thesis, he argues that in early Chinese thought, some key concepts from the Western tradition of philosophy\u2014such as truth and belief\u2014did not play a particularly important role in understanding knowledge. Meanwhile, action and the capacity for correct action constitute the core elements of the Chinese conception of knowledge, forming a stark contrast with the JTB-like account of knowledge that excludes the factor of action.<\/span><\/p><p><span data-mpa-action-id=\"mav3ib4e5v0\" data-pm-slice=\"0 0 []\">In this talk, I will introduce the three main chapters of his thesis. The thesis first discusses the problem of knowledge acquisition. In early China, people agreed that knowledge derives on one hand from the heart-mind (\u5fc3) and sensory organs, and on the other hand from practical training or cultivation leading. However, philosophers had fundamental disagreements about what ultimately determines what counts as knowledge. Secondly, knowledge was generally conceived as systematically correct action, and thus linguistic knowledge is the correct use of language. Language plays a crucial role in expressing and transmitting knowledge, and can therefore guide action to make it conform to the correct\u00a0dao. This key function depends on objective standards for language use, but the standards was challenged by skepticism. The thesis finally discusses Zhuangzi\u2019s skepticism and argues that his skepticism to some extent improved our epistemic position.<\/span><\/p><p data-mpa-action-id=\"mav4f05q1ram\" data-pm-slice=\"0 0 []\"><span data-mpa-action-id=\"mav3ib4e5v0\" data-pm-slice=\"0 0 []\">References<\/span><\/p><p data-mpa-action-id=\"mav4f05q1ram\" data-pm-slice=\"0 0 []\">1. Donald Sturgeon, 2014.\u00a0Knowledge in Early Chinese Thought. Ph.D Thesis, University of Hong Kong.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1166\" class=\"elementor-tab-title\" data-tab=\"6\" role=\"tab\" aria-controls=\"elementor-tab-content-1166\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 June 1 14:00-15:30 Ke Wu (\u5434\u53ef, Chinese University of Political Science and Law) The Convergence and Convergence Speed of Threshold Models in Social Networks<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1166\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"6\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1166\"><p><span data-mpa-action-id=\"mav3ib4e5v0\" data-pm-slice=\"0 0 []\">This talk presents a theoretical and computational study of belief dynamics in social networks using a threshold automaton model. We disprove the universal stability conjecture of belief convergence proposed by Liu et al. (2014), demonstrating instead that original formulation of the conjecture is exclusively achieved in finite, strongly connected networks. Our analysis establishes complete convergence conditions, generalizes stability criteria that extend beyond the original conjecture, and reveals that oscillating networks are equivalent to bipartite networks. The results provides a strict upper bound of time required for network stability, and by combining the six degrees of separation theory, it can be concluded that under this model, all humanity will stabilize in an extremely short time. These findings are further corroborated through experimental validation via simulation studies.<\/span><\/p><p data-mpa-action-id=\"mav4f05q1ram\" data-pm-slice=\"0 0 []\"><span data-mpa-action-id=\"mav3ib4e5v0\" data-pm-slice=\"0 0 []\">References<\/span><\/p><p data-mpa-action-id=\"mav4f05q1ram\" data-pm-slice=\"0 0 []\">1. Liu, F., Seligman, J. &amp; Girard, P. Logical dynamics of belief change in the community.\u00a0Synthese\u00a0191, 2403\u20132431 (2014).\u00a0https:\/\/doi.org\/10.1007\/s11229-014-0432-3<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1167\" class=\"elementor-tab-title\" data-tab=\"7\" role=\"tab\" aria-controls=\"elementor-tab-content-1167\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"\" class=\"elementor-toggle-title\">2025 June 12 14:00-15:30 Rui Zhu (\u795d\u745e, University of Auckland) How to Handle Arbitrary Announcement Operators: Completeness and Model Transformation in Social Announcement Logic<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1167\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"7\" role=\"tabpanel\" aria-labelledby=\"elementor-tab-title-1167\"><p>Arbitrary announcement operators are dynamic modalities that quantify over all possible messages that can be announced. They enable the expression of whether a given formula remains valid under any such announcement, thereby significantly enhancing the expressive power of Social Announcement Logic (SAL) in modeling information flow. However, incorporating such operators presents major formal challenges, particularly in proving the soundness of inference rules and establishing finitary completeness. In this work, we introduce a model transformation technique that provides a soundness proof for key inference rules involving arbitrary announcements. Based on this result, we construct a finitary axiomatization of SAL and prove its weak completeness using a standard Henkin-style method. We conclude by discussing the potential application of this technique to more complex scenarios, including reasoning about higher-order beliefs and dynamic changes in network structure. This talk is based on a paper accepted for presentation at LORI 2025.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Sessions in 2025-2026 Fall Semester\u00a0DateSpeaker2025 Nov [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/pages\/9653"}],"collection":[{"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/comments?post=9653"}],"version-history":[{"count":37,"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/pages\/9653\/revisions"}],"predecessor-version":[{"id":10040,"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/pages\/9653\/revisions\/10040"}],"wp:attachment":[{"href":"https:\/\/tsinghualogic.net\/JRC\/wp-json\/wp\/v2\/media?parent=9653"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}