{"title":"On the completenes principle: A study of provability in heyting's arithmetic and extensions","authors":"Albert Visser","doi":"10.1016/0003-4843(82)90024-9","DOIUrl":null,"url":null,"abstract":"<div><p>In this paper extensions of HA are studied that prove their own completeness, i.e. they prove <em>A</em> → □ <em>A</em>, where □ is interpreted as provability in the theory itself. Motivation is three-fold: (1) these theories are thought to have some intrinsic interest, (2) they are a tool for producing and studying provability principles, (3) they can be used to proved independence results. Work done in the paper connected with these motivations is respectively: </p><ul><li><span>1.</span><span><p>(i) A characterization is given of theories proving their own completeness, including an appropriate conservation result.</p></span></li><li><span>2.</span><span><p>(ii) Some new provability principles are produced. The provability logic of HA is not a sublogic of the of PA. A provability logic plus completeness theorem is given for a certain intuitionistic extension of HA. De Jongh's theorem for propositional logic is a corollary.</p></span></li><li><span>3.</span><span><p>(iii) FP-realizability in Beeson's proof that <span><math><mtext>∦</mtext><msub><mi></mi><mn><mtext>HA</mtext></mn></msub></math></span> KLS is replaced by theories proving their own completeness. New consequences are <span><math><mtext>∦</mtext><msub><mi></mi><mn><mtext>HA</mtext><mtext>+−</mtext><mtext>M</mtext><msub><mi></mi><mn>PR</mn></msub></mn></msub><mtext> </mtext><mtext>KLS</mtext></math></span>, <span><math><mtext>∦</mtext><msub><mi></mi><mn><mtext>HA+DNS</mtext></mn></msub><mtext> </mtext><mtext>KLS</mtext></math></span>.</p></span></li></ul></div>","PeriodicalId":100093,"journal":{"name":"Annals of Mathematical Logic","volume":"22 3","pages":"Pages 263-295"},"PeriodicalIF":0.0000,"publicationDate":"1982-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0003-4843(82)90024-9","citationCount":"53","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annals of Mathematical Logic","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0003484382900249","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 53
Abstract
In this paper extensions of HA are studied that prove their own completeness, i.e. they prove A → □ A, where □ is interpreted as provability in the theory itself. Motivation is three-fold: (1) these theories are thought to have some intrinsic interest, (2) they are a tool for producing and studying provability principles, (3) they can be used to proved independence results. Work done in the paper connected with these motivations is respectively:
1.
(i) A characterization is given of theories proving their own completeness, including an appropriate conservation result.
2.
(ii) Some new provability principles are produced. The provability logic of HA is not a sublogic of the of PA. A provability logic plus completeness theorem is given for a certain intuitionistic extension of HA. De Jongh's theorem for propositional logic is a corollary.
3.
(iii) FP-realizability in Beeson's proof that KLS is replaced by theories proving their own completeness. New consequences are , .