Dear all,
We will have our next LIRa session on Thursday, May 28th. Our speaker is Chenwei Shi. You will receive the zoom link and a reminder of the guidelines for online sessions the day before the talk. After the talk, we will continue the discussion with (online) drinks, as usual. You can find the details below.
Speaker: Chenwei Shi (Department of Philosophy, Tsinghua University, Beijing)
Date and Time: Thursday, May 28th 2020, 16:30-18:00, Amsterdam time.
Venue: online.
Title: Logic of Convex Order (Joint work with Yang Sun)
Abstract. Given a preference order on a set of possible worlds, there are different ways of extending/lifting it to a preference order on sets of worlds. For example, A >= B if and only if for all elements b in B there is an element a in A such that a >= b. This way of lifting order is usually named after Lewis, called l-lifting. In this talk, I will focus on another well-known way of order lifting, called "Egli-Milner ordering". Compared with the l-lifting, it only adds one more condition: for all elements a in A there is an element b in B such that a >= b. In this talk, I will examine the resulting logic of the Egli-Milner order. By presenting a sound and complete axiom system, I will show that the Egli-Milner order is "convex", which can be seen as a weaker form of monotonicity. To further illustrate the non-monotonicity of the Egli-Milner order, I will then discuss the relation between l-lifting, Egli-Milner order and conditional belief defined in a plausibility model.
Hope to see you there!
The LIRa team