{"title":"Closed left-r.e. sets","authors":"Sanjay Jain, F. Stephan, Jason Teutsch","doi":"10.3233/COM-160054","DOIUrl":null,"url":null,"abstract":"A set is called r-closed left-r.e. iff every set r-reducible to it is also a left-r.e. set. It is shown that some but not all left-r.e. cohesive sets are many-one closed left-r.e. sets. Ascending reductions are manyone reductions via an ascending function; left-r.e. cohesive sets are also ascening closed left-r.e. sets. Furthermore, it is shown that there is a weakly 1-generic many-one closed left-r.e. set.","PeriodicalId":53933,"journal":{"name":"De Computis-Revista Espanola de Historia de la Contabilidad","volume":"103 1","pages":"218-229"},"PeriodicalIF":0.2000,"publicationDate":"2011-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"De Computis-Revista Espanola de Historia de la Contabilidad","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3233/COM-160054","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 3
Abstract
A set is called r-closed left-r.e. iff every set r-reducible to it is also a left-r.e. set. It is shown that some but not all left-r.e. cohesive sets are many-one closed left-r.e. sets. Ascending reductions are manyone reductions via an ascending function; left-r.e. cohesive sets are also ascening closed left-r.e. sets. Furthermore, it is shown that there is a weakly 1-generic many-one closed left-r.e. set.