Model theory
Model theory
复制标题
模型理论
DOI:
10.1017/cbo9780511551574
复制
发表时间:
1993
期刊:
影响因子:
--
通讯作者:
Wilfrid Hodges
中科院分区:
文献类型:
--
作者:
Wilfrid Hodges
In 1954 Alfred Tarski [210] announced that ‘a new branch of metamathematics’ had appeared under the name of the theory of models. The subject grew fast: the Omega Group bibliography of model theory in 1987 [148] ran to 617 pages. By the mid 1980s there were already too many dialects of model theory for anybody to be expert in more than a fraction. For example very few model theorists could claim to understand both the work of Zilber and Hrushovski at the edge of algebraic geometry, and the studies by Immerman and Vardi of classifications of finite structures. And neither of these lines of research had much contact with what English-speaking philosophers and European computational linguists had come to refer to as ‘model-theoretic’ methods or concepts. Nevertheless all these brands of model theory had common origins and important family resemblances. Some other things called models definitely lie outside the family. For example this chapter has nothing to say about ‘modelling’, which means constructing a formal theory to describe or explain some phenomena. Likewise in cognitive science the ‘mental models’ of Gentner and Stephens [67] or Johnson-Laird [100] lie outside our topic. All the flavours of model theory rest on one fundamental notion, and that is the notion of a formula φ being true under an interpretation I. The classic treatment is Tarski’s paper [202] from 1933. In this paper Tarski supposes that we have a language L with a precisely defined syntax. Ignoring punctuation, the symbols of L are of two kinds: constants and variables. The constants have fixed meanings; they will usually include logical expressions such as ‘and’ and ‘equals’. The variables have no meaning, but (to shortcircuit Tarski’s very careful formulation a little) we can assign an object to each variable, and ask whether a given formula φ of L becomes true when each variable is regarded as a name of its assigned object. The grammatical categories of the variables determine what kinds of object can be assigned to them; for example we can assign individuals to individual variables, classes
DOI:
--
发表时间:
2022
期刊:
数理解析研究所考究録
影响因子:
--
作者:
Egashira Kento;Yata Kazuyoshi;Aoshima Makoto;Toshimichi Usuba;只木孝太郎;Kenta Ozeki;野崎寛;薄葉季路
通讯作者:
薄葉季路