Mathematical Logic Quarterly最新文献

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Apartness relations between propositions 命题之间的分离关系
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-11-14 DOI: 10.1002/malq.202300055
Zoltan A. Kocsis
{"title":"Apartness relations between propositions","authors":"Zoltan A. Kocsis","doi":"10.1002/malq.202300055","DOIUrl":"https://doi.org/10.1002/malq.202300055","url":null,"abstract":"<p>We classify all apartness relations definable in propositional logics extending intuitionistic logic using Heyting algebra semantics. We show that every Heyting algebra which contains a non-trivial apartness term satisfies the weak law of excluded middle, and every Heyting algebra which contains a tight apartness term is in fact a Boolean algebra. This answers a question of Rijke regarding the correct notion of apartness for propositions, and yields a short classification of apartness terms that can occur in a Heyting algebra. We also show that Martin-Löf Type Theory is not able to construct non-trivial apartness relations between propositions.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 4","pages":"414-428"},"PeriodicalIF":0.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142861168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On collection schemes and Gaifman's splitting theorem 关于集合格式和Gaifman的分裂定理
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-11-10 DOI: 10.1002/malq.202400021
Taishi Kurahashi, Yoshiaki Minami
{"title":"On collection schemes and Gaifman's splitting theorem","authors":"Taishi Kurahashi,&nbsp;Yoshiaki Minami","doi":"10.1002/malq.202400021","DOIUrl":"https://doi.org/10.1002/malq.202400021","url":null,"abstract":"<p>We study model theoretic characterizations of various collection schemes over <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>PA</mi>\u0000 <mo>−</mo>\u0000 </msup>\u0000 <annotation>$mathsf {PA}^-$</annotation>\u0000 </semantics></math> from the viewpoint of Gaifman's splitting theorem. Among other things, we prove that for any <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>n</mi>\u0000 <mo>≥</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation>$n ge 0$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>M</mi>\u0000 <mo>⊧</mo>\u0000 <msup>\u0000 <mi>PA</mi>\u0000 <mo>−</mo>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$M models mathsf {PA}^-$</annotation>\u0000 </semantics></math>, the following are equivalent: \u0000\u0000 </p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 4","pages":"398-413"},"PeriodicalIF":0.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Perfectly normal nonrealcompact spaces under Martin's Maximum 马丁极大值下的完全正规非实紧空间
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-10-16 DOI: 10.1002/malq.202400002
Tetsuya Ishiu
{"title":"Perfectly normal nonrealcompact spaces under Martin's Maximum","authors":"Tetsuya Ishiu","doi":"10.1002/malq.202400002","DOIUrl":"https://doi.org/10.1002/malq.202400002","url":null,"abstract":"&lt;p&gt;We analyze the behavior of a perfectly normal nonrealcompact space &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$(omega _1, tau)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; on &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$omega _1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; such that for every &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$gamma &lt;omega _1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;annotation&gt;$gamma$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;annotation&gt;$tau$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-open and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$gamma +omega$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;annotation&gt;$tau$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-closed under Martin's Maximum. We show that there exists a club subset &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;D&lt;/mi&gt;\u0000 &lt;annotation&gt;$D$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ω&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;$omega _1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; such that for a stationary subset of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mo&gt;∈&lt;/mo&gt;\u0000 &lt;mo&gt;acc&lt;/mo&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;D&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$delta in operatorname{acc}(D)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, for all &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;annot","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 4","pages":"388-397"},"PeriodicalIF":0.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202400002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142861588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Adding a constant and an axiom to a doctrine 为学说添加常数和公理
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-10-08 DOI: 10.1002/malq.202300053
Francesca Guffanti
{"title":"Adding a constant and an axiom to a doctrine","authors":"Francesca Guffanti","doi":"10.1002/malq.202300053","DOIUrl":"https://doi.org/10.1002/malq.202300053","url":null,"abstract":"<p>We study the meaning of “adding a constant to a language” for any doctrine, and “adding an axiom to a theory” for a primary doctrine, by showing how these are actually two instances of the same construction. We prove their universal properties, and how these constructions are compatible with additional structure on the doctrine. Existence of Kleisli object for comonads in the 2-category of indexed poset is proved in order to build these constructions.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 3","pages":"294-332"},"PeriodicalIF":0.4,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142404689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Paradoxical decompositions of free F 2 $F_2$ -sets and the Hahn-Banach axiom 自由F_2$ F_2$集的悖论分解与Hahn-Banach公理
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-10-03 DOI: 10.1002/malq.202400003
Marianne Morillon
{"title":"Paradoxical decompositions of free \u0000 \u0000 \u0000 F\u0000 2\u0000 \u0000 $F_2$\u0000 -sets and the Hahn-Banach axiom","authors":"Marianne Morillon","doi":"10.1002/malq.202400003","DOIUrl":"https://doi.org/10.1002/malq.202400003","url":null,"abstract":"<p>Denoting by <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>F</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$F_2$</annotation>\u0000 </semantics></math> the free group over a two-element alphabet, we show in set-theory without the axiom of choice <span></span><math>\u0000 <semantics>\u0000 <mi>ZF</mi>\u0000 <annotation>$mathsf {ZF}$</annotation>\u0000 </semantics></math> that the existence of a (2, 2)-paradoxical decomposition of free <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>F</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$F_2$</annotation>\u0000 </semantics></math>-sets follows from the conjunction of a weakened consequence of the Hahn-Banach axiom and a weakened consequence of the axiom of choice for pairs. The existence in <span></span><math>\u0000 <semantics>\u0000 <mi>ZF</mi>\u0000 <annotation>$mathsf {ZF}$</annotation>\u0000 </semantics></math> of a paradoxical decomposition with 4 pieces of the sphere in the 3-dimensional euclidean space follows from the same two statements restricted to the set <span></span><math>\u0000 <semantics>\u0000 <mi>R</mi>\u0000 <annotation>$mathbb {R}$</annotation>\u0000 </semantics></math> of real numbers. Our result is linked to the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>m</mi>\u0000 <mo>,</mo>\u0000 <mi>n</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$(m,n)$</annotation>\u0000 </semantics></math>-paradoxical decompositions of free <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>F</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>$F_2$</annotation>\u0000 </semantics></math>-sets previously obtained by Pawlikowski (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>=</mo>\u0000 <mi>n</mi>\u0000 <mo>=</mo>\u0000 <mn>3</mn>\u0000 </mrow>\u0000 <annotation>$m=n=3$</annotation>\u0000 </semantics></math>, cf. [11]) and then by Sato and Shioya (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>=</mo>\u0000 <mn>3</mn>\u0000 </mrow>\u0000 <annotation>$m=3$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>n</mi>\u0000 <mo>=</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$n=2$</annotation>\u0000 </semantics></math>, cf. [13]) with the sole Hahn-Banach axiom.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 4","pages":"367-387"},"PeriodicalIF":0.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A note on the cardinality of definable families of sets in o-minimal structures 关于0 -极小结构中可定义集合族的基数性的注记
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-09-22 DOI: 10.1002/malq.202300030
Pablo Andújar Guerrero
{"title":"A note on the cardinality of definable families of sets in o-minimal structures","authors":"Pablo Andújar Guerrero","doi":"10.1002/malq.202300030","DOIUrl":"https://doi.org/10.1002/malq.202300030","url":null,"abstract":"<p>We prove that any definable family of subsets of a definable infinite set <span></span><math>\u0000 <semantics>\u0000 <mi>A</mi>\u0000 <annotation>$A$</annotation>\u0000 </semantics></math> in an o-minimal structure has cardinality at most <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>|</mo>\u0000 <mi>A</mi>\u0000 <mo>|</mo>\u0000 </mrow>\u0000 <annotation>$|A|$</annotation>\u0000 </semantics></math>. We derive some consequences in terms of counting definable types and existence of definable topological spaces.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 4","pages":"361-366"},"PeriodicalIF":0.4,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202300030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The set of injections and the set of surjections on a set 注入集合和射出集
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-09-16 DOI: 10.1002/malq.202300059
Natthajak Kamkru, Nattapon Sonpanow
{"title":"The set of injections and the set of surjections on a set","authors":"Natthajak Kamkru,&nbsp;Nattapon Sonpanow","doi":"10.1002/malq.202300059","DOIUrl":"https://doi.org/10.1002/malq.202300059","url":null,"abstract":"&lt;p&gt;In this paper, we investigate the relationships between the cardinalities of the set of injections, the set of surjections, and the set of all functions on a set which is of cardinality &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;annotation&gt;$mathfrak {m}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, denoted by &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;I&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$I(mathfrak {m})$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;J&lt;/mi&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$J(mathfrak {m})$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;/msup&gt;\u0000 &lt;annotation&gt;$mathfrak {m}^mathfrak {m}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, respectively. Among our results, we show that “&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt;seq&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;≠&lt;/mo&gt;\u0000 &lt;mi&gt;I&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;≠&lt;/mo&gt;\u0000 &lt;mo&gt;seq&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$operatorname{seq}^{1-1}(mathfrak {m})ne I(mathfrak {m})ne operatorname{seq}(mathfrak {m})$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;”, “&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt;seq&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;≠&lt;/mo&gt;\u0000 &lt;mi&gt;J&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;≠&lt;/","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 3","pages":"275-285"},"PeriodicalIF":0.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142404725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effectiveness of Walker's cancellation theorem 沃克取消定理的有效性
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-09-13 DOI: 10.1002/malq.202400030
Layth Al-Hellawi, Rachael Alvir, Barbara F. Csima, Xinyue Xie
{"title":"Effectiveness of Walker's cancellation theorem","authors":"Layth Al-Hellawi,&nbsp;Rachael Alvir,&nbsp;Barbara F. Csima,&nbsp;Xinyue Xie","doi":"10.1002/malq.202400030","DOIUrl":"10.1002/malq.202400030","url":null,"abstract":"&lt;p&gt;Walker's cancellation theorem for abelian groups tells us that if &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;annotation&gt;$A$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is finitely generated and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;annotation&gt;$G$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;annotation&gt;$H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; are such that &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mi&gt;⊕&lt;/mi&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mo&gt;≅&lt;/mo&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mi&gt;⊕&lt;/mi&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$A oplus G cong A oplus H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, then &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;mo&gt;≅&lt;/mo&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$G cong H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Deveau showed that the theorem can be effectivized, but not uniformly. In this paper, we expand on Deveau's initial analysis to show that the complexity of uniformly outputting an index of an isomorphism between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;annotation&gt;$G$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;annotation&gt;$H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, given indices for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;annotation&gt;$A$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;annotation&gt;$G$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;annotation&gt;$H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, the isomorphism between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mi&gt;⊕&lt;/mi&gt;\u0000 &lt;mi&gt;G&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$A oplus G$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mi&gt;⊕&lt;/mi&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$A oplus H$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and the rank of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 ","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 3","pages":"347-355"},"PeriodicalIF":0.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202400030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Good points for scales (and more) 天平的优点(以及更多)
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-09-09 DOI: 10.1002/malq.202300034
Pierre Matet
{"title":"Good points for scales (and more)","authors":"Pierre Matet","doi":"10.1002/malq.202300034","DOIUrl":"10.1002/malq.202300034","url":null,"abstract":"<p>Given a scale (in the sense of Shelah's pcf theory), we list various conditions ensuring that a given point is good for the scale.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 3","pages":"333-346"},"PeriodicalIF":0.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142182741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Editorial correction for L. Halbeisen, R. Plati, and Saharon Shelah, “Implications of Ramsey Choice principles in ZF $mathsf {ZF}$ ”, https://doi.org/10.1002/malq.202300024 对 L. Halbeisen、R. Plati 和 Saharon Shelah "拉姆齐选择原则在 ZF$mathsf {ZF}$ 中的影响 "的编辑更正,https://doi.org/10.1002/malq.202300024。
IF 0.4 4区 数学
Mathematical Logic Quarterly Pub Date : 2024-09-09 DOI: 10.1002/malq.202430002
{"title":"Editorial correction for L. Halbeisen, R. Plati, and Saharon Shelah, “Implications of Ramsey Choice principles in \u0000 \u0000 ZF\u0000 $mathsf {ZF}$\u0000 ”, https://doi.org/10.1002/malq.202300024","authors":"","doi":"10.1002/malq.202430002","DOIUrl":"10.1002/malq.202430002","url":null,"abstract":"<p>The numbers of corollaries and propositions in the proof of Theorem 3.8 on p. 260 in the article <i>Implications of Ramsey Choice principles in</i> <span></span><math>\u0000 <semantics>\u0000 <mi>ZF</mi>\u0000 <annotation>$mathsf {ZF}$</annotation>\u0000 </semantics></math> by Lorenz Halbeisen, Riccardo Plati, and Saharon Shelah (doi: 10.1002/malq.202300024) are incorrect. The correct numbers are given here:</p><p>August 2024</p><p>The MLQ Editorial Office</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"70 3","pages":"356"},"PeriodicalIF":0.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202430002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142182740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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