Galois Connection between Syntax and Semantics

 

Peter Fritz intro to propositional quantifiers里提到的 有点想去WG上讲

(Update (Jun 18 2023): 最后在DRP讲了!)

链接

[1 Peter Smith 的文章] [2前面那个文章的post] [3比较简短的介绍] [peter smith更general的intro][5知乎]

abstract interpretation 也有应用(开山?论文) 有课件:[版本一] [版本二] 跟topology的联系

Awodey课本 p.219-p.225 也有讲

Blackburn的modal logic课本有道习题也相关 p.217 引了一篇paper

Peter Smith 文章笔记

顺序:建立 poset 的一些基本概念 (最重要的是inclusion posets: you can build a complete lattice out of any set),然后讲 Galois Connection定义 及一堆推论 等价定义,uniqueness,closure;最后是重要的连接:

主要想法:

Def 3.2.1: Let A be the set of all L-sentences, and S be the set of all L-structures. Then put

  1. $\mathscr{A} = \langle \mathcal{P}(A), \subseteq \rangle$.

  2. $\mathscr{S} = \langle \mathcal{P}(S), \supseteq \rangle$.

  3. For $\alpha \subseteq A$, put $f_*(\sigma) =$ { $s$ $ | $ $\forall \varphi (\varphi \in \alpha \to s \models \varphi) $}

  4. For $\sigma \subseteq S$, put $f^*(\sigma) =$ { $\varphi$ $ | $ $\forall s (s \in \sigma \to s \models \varphi) $}

Then, $\langle f_* , f^* \rangle$ is a galois connection between $\mathscr{A} \text{ and } \mathscr{S}$.