2026 Apr 16 14:00-15:30 Andrew Arana (University of Lorraine) An Introduction to Purity of Methods

A proof of a theorem can be said to be pure if it draws only on what is “close” or “intrinsic” to that theorem. In this talk, we will introduce the apparent preference for pure proofs that has persisted in mathematics since antiquity, alongside a competing preference for impurity… More>>

2026 Apr 9 14:00-15:30 Wenlong Zheng (郑文龙, Tsinghua University) Nonmonotonicity and Actual Causation: The Theory of Bochman’s Causal Calculus

Causality is a fundamental concept in reasoning, yet capturing its exact formal semantics has historically posed a challenge for standard deductive systems. In his 2021 book A Logical Theory of Causality, Alexander Bochman develops a causal calculus based on rules of the form A\Rightarrow B  (“A causes B”), situated within a nonmonotonic reasoning framework. By treating causal rules as default assumptions, we will see how causal reasoning emerges as a special instance of nonmonotonic reasoning developed within the knowledge representation and symbolic branches of artificial intelligence….More>>

2026 Mar 19 14:00-15:30 Wenfei Ouyang (欧阳文飞, Tsinghua University) 余代数与模态逻辑

本期进阶读书会将于 2026年3月19日（周四）14:00-15:30 在清华大学逻辑学中心举行，由清华大学欧阳文飞同学报告 Yde Venema 编写的讲义 Coalgebra and Modal Logic: A First Introduction 的 1.2 节，重点介绍模态逻辑的 bounded morphism 在 coalgebra 中的定义。More>>