{"title":"A good lightface Δn1 well-ordering of the reals does not imply the existence of boldface Δn−11 well-orderings","authors":"Vladimir Kanovei, Vassily Lyubetsky","doi":"10.1016/j.apal.2024.103426","DOIUrl":null,"url":null,"abstract":"<div><p>We make use of a finite support product of the Jensen-type forcing notions to define a model of the set theory <span><math><mtext>ZFC</mtext></math></span> in which, for a given <span><math><mi>n</mi><mo>≥</mo><mn>3</mn></math></span>, there exists a good lightface <span><math><msubsup><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi></mrow><mrow><mn>1</mn></mrow></msubsup></math></span> well-ordering of the reals but there are no any (not necessarily good) well-orderings in the boldface class <span><math><msubsup><mrow><mi>Δ</mi></mrow><mrow><mi>n</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>1</mn></mrow></msubsup></math></span>.</p></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"175 6","pages":"Article 103426"},"PeriodicalIF":0.6000,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annals of Pure and Applied Logic","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S016800722400023X","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"LOGIC","Score":null,"Total":0}
引用次数: 0
Abstract
We make use of a finite support product of the Jensen-type forcing notions to define a model of the set theory in which, for a given , there exists a good lightface well-ordering of the reals but there are no any (not necessarily good) well-orderings in the boldface class .
期刊介绍:
The journal Annals of Pure and Applied Logic publishes high quality papers in all areas of mathematical logic as well as applications of logic in mathematics, in theoretical computer science and in other related disciplines. All submissions to the journal should be mathematically correct, well written (preferably in English)and contain relevant new results that are of significant interest to a substantial number of logicians. The journal also considers submissions that are somewhat too long to be published by other journals while being too short to form a separate memoir provided that they are of particular outstanding quality and broad interest. In addition, Annals of Pure and Applied Logic occasionally publishes special issues of selected papers from well-chosen conferences in pure and applied logic.