Emmanuel Gunther , Miguel Pagano , Pedro Sánchez Terraf , Matías Steinberg
{"title":"The formal verification of the ctm approach to forcing","authors":"Emmanuel Gunther , Miguel Pagano , Pedro Sánchez Terraf , Matías Steinberg","doi":"10.1016/j.apal.2024.103413","DOIUrl":null,"url":null,"abstract":"<div><p>We discuss some highlights of our computer-verified proof of the construction, given a countable transitive set-model <em>M</em> of <em>ZFC</em>, of generic extensions satisfying <span><math><mrow><mi>ZFC</mi></mrow><mo>+</mo><mo>¬</mo><mrow><mi>CH</mi></mrow></math></span> and <span><math><mrow><mi>ZFC</mi></mrow><mo>+</mo><mrow><mi>CH</mi></mrow></math></span>. Moreover, let <span><math><mi>R</mi></math></span> be the set of instances of the Axiom of Replacement. We isolated a 21-element subset <span><math><mi>Ω</mi><mo>⊆</mo><mi>R</mi></math></span> and defined <span><math><mi>F</mi><mo>:</mo><mi>R</mi><mo>→</mo><mi>R</mi></math></span> such that for every <span><math><mi>Φ</mi><mo>⊆</mo><mi>R</mi></math></span> and <em>M</em>-generic <em>G</em>, <span><math><mi>M</mi><mo>⊨</mo><mrow><mi>ZC</mi></mrow><mo>∪</mo><mi>F</mi><mtext>“</mtext><mi>Φ</mi><mo>∪</mo><mi>Ω</mi></math></span> implies <span><math><mi>M</mi><mo>[</mo><mi>G</mi><mo>]</mo><mo>⊨</mo><mrow><mi>ZC</mi></mrow><mo>∪</mo><mi>Φ</mi><mo>∪</mo><mo>{</mo><mo>¬</mo><mrow><mi>CH</mi></mrow><mo>}</mo></math></span>, where <em>ZC</em> is Zermelo set theory with Choice.</p><p>To achieve this, we worked in the proof assistant <em>Isabelle</em>, basing our development on the Isabelle/ZF library by L. Paulson and others.</p></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"175 5","pages":"Article 103413"},"PeriodicalIF":0.6000,"publicationDate":"2024-01-30","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/S0168007224000101","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 discuss some highlights of our computer-verified proof of the construction, given a countable transitive set-model M of ZFC, of generic extensions satisfying and . Moreover, let be the set of instances of the Axiom of Replacement. We isolated a 21-element subset and defined such that for every and M-generic G, implies , where ZC is Zermelo set theory with Choice.
To achieve this, we worked in the proof assistant Isabelle, basing our development on the Isabelle/ZF library by L. Paulson and others.
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.