第三十二期  逸仙逻辑讲坛

题目：匿名公开宣告逻辑（The Logic of Anonymous Public Announcements）

主讲人：Thomas Ågotnes

挪威卑尔根大学信息科学与媒体研究系教授、山西大学哲学学院兼职教授

主持人：刘虎  教授

抢庄牛牛-抢庄牛牛规则 逻辑与认知研究所

时   间：4月25日（周五）上午 10:30

地   点：中山大学锡昌堂 708 室

主办方：中山大学逻辑与认知研究所

主讲人简介 

       Thomas Ågotnes，挪威卑尔根大学信息科学与媒体研究系教授，山西大学哲学学院兼职教授，教育部长江学者讲座教授。主要从事多主体系统、认知逻辑、博弈论和社会选择、社会网络等交叉领域的研究。他在Artificial Intelligence、Synthese、JAAMAS、JLC、JoLLI、Logic Journal of IGPL、Studia Logica等国际顶尖期刊和AAAI、IJCAI、AAMAS、KR、ECAI、TARK等逻辑学和人工智能领域国际权威会议上发表论文百余篇，其中多篇论文曾获会议最佳论文奖。并曾获得挪威卑尔根学院（现西挪威应用科学大学)“研究进步奖”。他目前担任多主体系统欧洲联合会（EURAMAS）和挪威人工智能学会理事会理事，多主体系统可计算性逻辑（CLIMA）国际大会和多主体系统中的逻辑（LAMAS）等知名国际会议的指导委员会委员。

内容简介 

       我们在公开宣告逻辑的框架下，形式化了匿名公开宣告。此类宣告可视为介于外部宣告（经典公开宣告）和个体宣告（宣告Ka φ）之间的一种类型。尽管宣告本身匿名，但结合背景知识，宣告者身份仍可能被揭露。此外，正如“俄罗斯卡牌”问题所示，若“发布者意图保持匿名”成为公共知识，则可能泄露更多信息。我们首先探讨无意图假设下的匿名公开宣告，证明其逻辑可归约为经典认知逻辑。然后进一步探讨匿名意图成为公共知识这一更为复杂的情形——它与“安全”宣告概念相关（也与俄罗斯卡牌相似）。报告基于与Rustam Galimullin, Ken Satoh 和 Satoshi Tojo的合作研究。

       We formalise the notion of an anonymous public announcement in the tradition of public announcement logic. Such announcements can be seen as in-between a public announcement from "the outside" (an announcement of φ) and a public announcement by one of the agents (an announcement of Kaφ we get more information than just φ but not (necessarily) about exactly who made it. Even if such an announcement is prima facie anonymous, depending on the background knowledge of the agents it might reveal the identity of the announcer: if I post something on a message board, the information might reveal who I am even if I don't sign my name. Furthermore, like in the Russian Cards puzzle, if we assume that the announcer's intention was to stay anonymous, that in fact might reveal more information. In this paper we first look at the case when no assumption about intentions are made, in which case the logic with an anonymous public announcement operator is reducible to epistemic logic. We then look at the case when we assume common knowledge of the intention to stay anonymous, which is both more complex and more interesting: in several ways it boils down to the notion of a "safe" announcement (again, similarly to Russian Cards). Main results include formal expressivity results and axiomatic completeness for key logical languages. The talk is based on joint work with Rustam Galimullin, Ken Satoh and Satoshi Tojo.