{"title":"Definability in affine logic","authors":"Seyed-Mohammad Bagheri","doi":"10.1007/s00153-025-00972-7","DOIUrl":null,"url":null,"abstract":"<div><p>I study definability notions in the framework of affine continuous logic. Some general results concerning types and definable relations in affinely complete theories are proved. If the theory has a first order model, its extremal theory is a complete first order theory and first order definable sets are affinely definable. If it has a compact model, definable sets are exactly the end-sets of definable predicates. As an example, it is proved in the theory of probability algebras that one dimensional definable sets are exactly the intervals [<i>a</i>, <i>b</i>].</p></div>","PeriodicalId":48853,"journal":{"name":"Archive for Mathematical Logic","volume":"64 7-8","pages":"973 - 995"},"PeriodicalIF":0.5000,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archive for Mathematical Logic","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s00153-025-00972-7","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Arts and Humanities","Score":null,"Total":0}
引用次数: 0
Abstract
I study definability notions in the framework of affine continuous logic. Some general results concerning types and definable relations in affinely complete theories are proved. If the theory has a first order model, its extremal theory is a complete first order theory and first order definable sets are affinely definable. If it has a compact model, definable sets are exactly the end-sets of definable predicates. As an example, it is proved in the theory of probability algebras that one dimensional definable sets are exactly the intervals [a, b].
期刊介绍:
The journal publishes research papers and occasionally surveys or expositions on mathematical logic. Contributions are also welcomed from other related areas, such as theoretical computer science or philosophy, as long as the methods of mathematical logic play a significant role. The journal therefore addresses logicians and mathematicians, computer scientists, and philosophers who are interested in the applications of mathematical logic in their own field, as well as its interactions with other areas of research.