Title: Tense logic: Points and Periods

Speaker:  Liqing Ruan (PKU)

Time: 15:10 ~ 18:00  (Nov. 29)

Tencent Meeting ID: 426 310 305

Abstract:  When we begin a conversation in English, we will find that we use verbs in different tenses, and the nature of this phenomenon is that we jump to other points (or periods) of time to think about sentences involved in the conversation. In this presentation, we will focus on "The Logic of Time" by van Benthem(1991) and explore the properties of time flow. Then we will introduce Prior's tense logic for pointed time flow and an extended version of it for periodic time flow. Finally, when we go deep into the completeness of these two logics, we will use the canonical methods and the unraveling skills, and also find that transformations between pointed time flow and the periodic one play important roles in the proof of completeness.