5月5日Jeremy Seligman报告: Common Sense Modal Predicate Logic

发布时间:2017-05-04 来源:本站原创 作者:本站编辑   浏览次数:

 题目:Common Sense Modal Predicate Logic


 报告人:Jeremy Seligman    

 时间:5月5日9:00-11:00  地点:逻辑与智能研究中心3203


ABSTRACT:

Modal Predicate Calculus (MPC) is the result of adding the S5 axioms and Necessitation rule to an axiomatic system for predicate logic. Famously, all instances of the Barcan scheme are theorems of MPC. When interpreted using possible world semantics, Barcan implies the strong metaphysical thesis that every world has the same domain of objects. We briefly survey some reasons for regarding this as unsatisfactory and propose a slight variant of both the semantics and the logical calculus to restore common sense. The calculus (CMPC) differs from MPC only in imposing a syntactic restriction on the K axiom scheme: □only distributes over implications for which the free variables of the antecedent also occur free in the con-sequent. Its theorems include the converse of Barcan but not Barcan and its semantics rejects the Constant Domain thesis.