{"title":"Th (N,·)$ \\operatorname{Th}(\\mathbb {N},\\cdot)$","authors":"Atticus Stonestrom","doi":"10.1002/malq.202100049","DOIUrl":null,"url":null,"abstract":"<p>‘Skolem arithmetic’ is the complete theory <i>T</i> of the multiplicative monoid <math>\n <semantics>\n <mrow>\n <mo>(</mo>\n <mi>N</mi>\n <mo>,</mo>\n <mo>·</mo>\n <mo>)</mo>\n </mrow>\n <annotation>$(\\mathbb {N},\\cdot )$</annotation>\n </semantics></math>. We give a full characterization of the <math>\n <semantics>\n <mi>⌀</mi>\n <annotation>$\\varnothing$</annotation>\n </semantics></math>-definable stably embedded sets of <i>T</i>, showing in particular that, up to the relation of having the same definable closure, there is only one non-trivial one: the set of squarefree elements. We then prove that <i>T</i> has weak elimination of imaginaries but not elimination of finite imaginaries.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"68 3","pages":"288-303"},"PeriodicalIF":0.4000,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202100049","citationCount":"1","resultStr":"{\"title\":\"Some model theory of \\n \\n \\n Th\\n (\\n N\\n ,\\n ·\\n )\\n \\n $\\\\operatorname{Th}(\\\\mathbb {N},\\\\cdot )$\",\"authors\":\"Atticus Stonestrom\",\"doi\":\"10.1002/malq.202100049\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>‘Skolem arithmetic’ is the complete theory <i>T</i> of the multiplicative monoid <math>\\n <semantics>\\n <mrow>\\n <mo>(</mo>\\n <mi>N</mi>\\n <mo>,</mo>\\n <mo>·</mo>\\n <mo>)</mo>\\n </mrow>\\n <annotation>$(\\\\mathbb {N},\\\\cdot )$</annotation>\\n </semantics></math>. We give a full characterization of the <math>\\n <semantics>\\n <mi>⌀</mi>\\n <annotation>$\\\\varnothing$</annotation>\\n </semantics></math>-definable stably embedded sets of <i>T</i>, showing in particular that, up to the relation of having the same definable closure, there is only one non-trivial one: the set of squarefree elements. We then prove that <i>T</i> has weak elimination of imaginaries but not elimination of finite imaginaries.</p>\",\"PeriodicalId\":49864,\"journal\":{\"name\":\"Mathematical Logic Quarterly\",\"volume\":\"68 3\",\"pages\":\"288-303\"},\"PeriodicalIF\":0.4000,\"publicationDate\":\"2022-04-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202100049\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Mathematical Logic Quarterly\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/malq.202100049\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"LOGIC\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Logic Quarterly","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.202100049","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"LOGIC","Score":null,"Total":0}
Some model theory of
Th
(
N
,
·
)
$\operatorname{Th}(\mathbb {N},\cdot )$
‘Skolem arithmetic’ is the complete theory T of the multiplicative monoid . We give a full characterization of the -definable stably embedded sets of T, showing in particular that, up to the relation of having the same definable closure, there is only one non-trivial one: the set of squarefree elements. We then prove that T has weak elimination of imaginaries but not elimination of finite imaginaries.
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.