{"title":"Ideal Analytic Sets","authors":"Łukasz Mazurkiewicz, Szymon Żeberski","doi":"10.1002/malq.70012","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>The aim of this study is to give natural examples of <span></span><math>\n <semantics>\n <mrow>\n <msubsup>\n <mi>Σ</mi>\n <mn>1</mn>\n <mn>1</mn>\n </msubsup>\n </mrow>\n <annotation>$\\operatorname{\\mathbf {\\Sigma }_1^1}$</annotation>\n </semantics></math>-complete and <span></span><math>\n <semantics>\n <mrow>\n <msubsup>\n <mi>Π</mi>\n <mn>1</mn>\n <mn>1</mn>\n </msubsup>\n </mrow>\n <annotation>$\\operatorname{\\mathbf {\\Pi }_1^1}$</annotation>\n </semantics></math>-complete sets.</p>\n <p>In the first part, we consider ideals on <span></span><math>\n <semantics>\n <mi>ω</mi>\n <annotation>$\\omega$</annotation>\n </semantics></math>. We use a unified approach introduced in [4] to create reductions of the collection of ill-founded trees to the ideals, proving <span></span><math>\n <semantics>\n <mrow>\n <msubsup>\n <mi>Σ</mi>\n <mn>1</mn>\n <mn>1</mn>\n </msubsup>\n </mrow>\n <annotation>$\\operatorname{\\mathbf {\\Sigma }_1^1}$</annotation>\n </semantics></math>-completeness of the ideals.</p>\n <p>In the second part, we show the connection between this topic, families of trees and coding of <span></span><math>\n <semantics>\n <mi>σ</mi>\n <annotation>$\\sigma$</annotation>\n </semantics></math>-ideals of Polish spaces. In particular, we use the unified approach to prove that sets of codes for closed Ramsey-null sets, for closed <span></span><math>\n <semantics>\n <mi>σ</mi>\n <annotation>$\\sigma$</annotation>\n </semantics></math>-compact sets and for closed not strongly dominating sets are <span></span><math>\n <semantics>\n <mrow>\n <msubsup>\n <mi>Π</mi>\n <mn>1</mn>\n <mn>1</mn>\n </msubsup>\n </mrow>\n <annotation>$\\operatorname{\\mathbf {\\Pi }_1^1}$</annotation>\n </semantics></math>-complete.</p></div>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"72 1","pages":""},"PeriodicalIF":0.4000,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Logic Quarterly","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.70012","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"LOGIC","Score":null,"Total":0}
引用次数: 0
Abstract
The aim of this study is to give natural examples of -complete and -complete sets.
In the first part, we consider ideals on . We use a unified approach introduced in [4] to create reductions of the collection of ill-founded trees to the ideals, proving -completeness of the ideals.
In the second part, we show the connection between this topic, families of trees and coding of -ideals of Polish spaces. In particular, we use the unified approach to prove that sets of codes for closed Ramsey-null sets, for closed -compact sets and for closed not strongly dominating sets are -complete.
期刊介绍:
Mathematical Logic Quarterly publishes original contributions on mathematical logic and foundations of mathematics and related areas, such as general logic, model theory, recursion theory, set theory, proof theory and constructive mathematics, algebraic logic, nonstandard models, and logical aspects of theoretical computer science.