{"title":"Positive definability patterns","authors":"Ori Segel","doi":"10.1016/j.apal.2024.103539","DOIUrl":"10.1016/j.apal.2024.103539","url":null,"abstract":"<div><div>We reformulate Hrushovski's definability patterns from the setting of first order logic to the setting of positive logic. Given an h-universal theory <em>T</em> we put two structures on the type spaces of models of <em>T</em> in two languages, <span><math><mi>L</mi></math></span> and <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>π</mi></mrow></msub></math></span>. It turns out that for sufficiently saturated models, the corresponding h-universal theories <span><math><mi>T</mi></math></span> and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>π</mi></mrow></msub></math></span> are independent of the model. We show that there is a canonical model <span><math><mi>J</mi></math></span> of <span><math><mi>T</mi></math></span>, and in many interesting cases there is an analogous canonical model <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>π</mi></mrow></msub></math></span> of <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>π</mi></mrow></msub></math></span>, both of which embed into every type space. We discuss the properties of these canonical models, called cores, and give some concrete examples.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 4","pages":"Article 103539"},"PeriodicalIF":0.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diego Castaño , José Patricio Díaz Varela , Gabriel Savoy
{"title":"Strong standard completeness theorems for S5-modal Łukasiewicz logics","authors":"Diego Castaño , José Patricio Díaz Varela , Gabriel Savoy","doi":"10.1016/j.apal.2024.103529","DOIUrl":"10.1016/j.apal.2024.103529","url":null,"abstract":"<div><div>We study the S5-modal expansion of the Łukasiewicz logic. We exhibit a finitary propositional calculus and show that it is finitely strongly complete with respect to this logic. This propositional calculus is then expanded with an infinitary rule to achieve strong completeness. These results are derived from properties of monadic MV-algebras: functional representations of simple and finitely subdirectly irreducible algebras, as well as the finite embeddability property. We also show similar completeness theorems for the extension of the logic based on models with bounded universe.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 3","pages":"Article 103529"},"PeriodicalIF":0.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Semiconic idempotent logic II: Beth definability and deductive interpolation","authors":"Wesley Fussner , Nikolaos Galatos","doi":"10.1016/j.apal.2024.103528","DOIUrl":"10.1016/j.apal.2024.103528","url":null,"abstract":"<div><div>Semiconic idempotent logic <strong>sCI</strong> is a common generalization of intuitionistic logic, semilinear idempotent logic <strong>sLI</strong>, and in particular relevance logic with mingle. We establish the projective Beth definability property and the deductive interpolation property for many extensions of <strong>sCI</strong>, and identify extensions where these properties fail. We achieve these results by studying the (strong) amalgamation property and the epimorphism-surjectivity property for the corresponding algebraic semantics, viz. semiconic idempotent residuated lattices. Our study is made possible by the structural decomposition of conic idempotent models achieved in the prequel, as well as a detailed analysis of the structure of idempotent residuated chains serving as index sets in this decomposition. Here we study the latter on two levels: as certain enriched Galois connections and as enhanced monoidal preorders. Using this, we show that although conic idempotent residuated lattices do not have the amalgamation property, the natural class of stratified and conjunctive conic idempotent residuated lattices has the strong amalgamation property, and thus has surjective epimorphisms. This extends to the variety generated by stratified and conjunctive conic idempotent residuated lattices, and we establish the (strong) amalgamation and epimorphism-surjectivity properties for several important subvarieties. Using the algebraizability of <strong>sCI</strong>, this yields the deductive interpolation property and the projective Beth definability property for the corresponding substructural logics extending <strong>sCI</strong>.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 3","pages":"Article 103528"},"PeriodicalIF":0.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Failure of the Blok–Esakia Theorem in the monadic setting","authors":"G. Bezhanishvili , L. Carai","doi":"10.1016/j.apal.2024.103527","DOIUrl":"10.1016/j.apal.2024.103527","url":null,"abstract":"<div><div>The Blok–Esakia Theorem establishes that the lattice of superintuitionistic logics is isomorphic to the lattice of extensions of Grzegorczyk's logic. We prove that the Blok–Esakia isomorphism <em>σ</em> does not extend to the fragments of the corresponding predicate logics of already one fixed variable. In other words, we prove that <em>σ</em> is no longer an isomorphism from the lattice of extensions of the monadic intuitionistic logic to the lattice of extensions of the monadic Grzegorczyk logic.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 4","pages":"Article 103527"},"PeriodicalIF":0.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Universal proof theory: Feasible admissibility in intuitionistic modal logics","authors":"Amirhossein Akbar Tabatabai , Raheleh Jalali","doi":"10.1016/j.apal.2024.103526","DOIUrl":"10.1016/j.apal.2024.103526","url":null,"abstract":"<div><div>We introduce a general and syntactically defined family of sequent-style calculi over the propositional language with the modalities <span><math><mo>{</mo><mo>□</mo><mo>,</mo><mo>◇</mo><mo>}</mo></math></span> and its fragments as a formalization for constructively acceptable systems. Calling these calculi <em>constructive</em>, we show that any strong enough constructive sequent calculus, satisfying a mild technical condition, feasibly admits all Visser's rules. This means that there exists a polynomial-time algorithm that, given a proof of the premise of a Visser's rule, provides a proof for its conclusion. As a positive application, we establish the feasible admissibility of Visser's rules in sequent calculi for several intuitionistic modal logics, including <span><math><mi>CK</mi></math></span>, <span><math><mi>IK</mi></math></span>, their extensions by the modal axioms <em>T</em>, <em>B</em>, 4, 5, and the axioms for bounded width and depth and their fragments <span><math><msub><mrow><mi>CK</mi></mrow><mrow><mo>□</mo></mrow></msub></math></span>, propositional lax logic and <span><math><mi>IPC</mi></math></span>. On the negative side, we show that if a strong enough intuitionistic modal logic (satisfying a mild technical condition) does not admit at least one of Visser's rules, it cannot have a constructive sequent calculus. Consequently, no intermediate logic other than <span><math><mi>IPC</mi></math></span> has a constructive sequent calculus.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103526"},"PeriodicalIF":0.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bi-colored expansions of geometric theories","authors":"S. Jalili , M. Pourmahdian , M. Khani","doi":"10.1016/j.apal.2024.103525","DOIUrl":"10.1016/j.apal.2024.103525","url":null,"abstract":"<div><div>This paper concerns the study of expansions of models of a geometric theory <em>T</em> by a color predicate <em>p</em>, within the framework of the Fraïssé-Hrushovski construction method. For each <span><math><mi>α</mi><mo>∈</mo><mo>(</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></math></span>, we define a pre-dimension function <span><math><msub><mrow><mi>δ</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> on the class of Bi-colored models of <span><math><msup><mrow><mi>T</mi></mrow><mrow><mo>∀</mo></mrow></msup></math></span> and consider the subclass <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>α</mi></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> consisting of models with hereditary positive <span><math><msub><mrow><mi>δ</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>. We impose certain natural conditions on <em>T</em> that enable us to introduce a complete <span><math><msub><mrow><mi>Π</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-theory <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> for the rich models in <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>α</mi></mrow><mrow><mo>+</mo></mrow></msubsup></math></span>. We show how the transfer of certain model-theoretic properties, such as NIP and strong-dependence, from <em>T</em> to <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>, depends on whether <em>α</em> is rational or irrational.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103525"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Equiconsistency of the Minimalist Foundation with its classical version","authors":"Maria Emilia Maietti, Pietro Sabelli","doi":"10.1016/j.apal.2024.103524","DOIUrl":"10.1016/j.apal.2024.103524","url":null,"abstract":"<div><div>The Minimalist Foundation, for short <strong>MF</strong>, was conceived by the first author with G. Sambin in 2005, and fully formalized in 2009, as a common core among the most relevant constructive and classical foundations for mathematics. To better accomplish its minimality, <strong>MF</strong> was designed as a two-level type theory, with an intensional level <strong>mTT</strong>, an extensional one <strong>emTT</strong>, and an interpretation of the latter into the first.</div><div>Here, we first show that the two levels of <strong>MF</strong> are indeed equiconsistent by interpreting <strong>mTT</strong> into <strong>emTT</strong>. Then, we show that the classical extension <span><math><msup><mrow><mi>emTT</mi></mrow><mrow><mi>c</mi></mrow></msup></math></span> is equiconsistent with <strong>emTT</strong> by suitably extending the Gödel-Gentzen double-negation translation of classical logic in the intuitionistic one. As a consequence, <strong>MF</strong> turns out to be compatible with classical predicative mathematics à la Weyl, contrary to the most relevant foundations for constructive mathematics.</div><div>Finally, we show that the chain of equiconsistency results for <strong>MF</strong> can be straightforwardly extended to its impredicative version to deduce that Coquand-Huet's Calculus of Constructions equipped with basic inductive types is equiconsistent with its extensional and classical versions too.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103524"},"PeriodicalIF":0.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Some properties of precompletely and positively numbered sets","authors":"Marat Faizrahmanov","doi":"10.1016/j.apal.2024.103523","DOIUrl":"10.1016/j.apal.2024.103523","url":null,"abstract":"<div><div>In this paper, we prove a joint generalization of Arslanov's completeness criterion and Visser's ADN theorem for precomplete numberings which, for the Gödel numbering <span><math><mi>x</mi><mo>↦</mo><msub><mrow><mi>W</mi></mrow><mrow><mi>x</mi></mrow></msub></math></span>, has been proved by Terwijn (2018). The question of whether this joint generalization takes place in each precomplete numbering has been raised in his joint paper with Barendregt in 2019. Then we consider the properties of completeness and precompleteness of numberings in the context of the positivity property. We show that no completion of a positive numbering is a minimal cover of that numbering, and that the Turing completeness of any set <em>A</em> is equivalent to the existence of a positive precomplete <em>A</em>-computable numbering of any infinite family with positive <em>A</em>-computable numbering. In addition, we prove that each <span><math><msubsup><mrow><mi>Σ</mi></mrow><mrow><mi>n</mi></mrow><mrow><mn>0</mn></mrow></msubsup></math></span>-computable numbering (<span><math><mi>n</mi><mo>⩾</mo><mn>2</mn></math></span>) of a <span><math><msubsup><mrow><mi>Σ</mi></mrow><mrow><mi>n</mi></mrow><mrow><mn>0</mn></mrow></msubsup></math></span>-computable non-principal family has a <span><math><msubsup><mrow><mi>Σ</mi></mrow><mrow><mi>n</mi></mrow><mrow><mn>0</mn></mrow></msubsup></math></span>-computable minimal cover <em>ν</em> such that for every computable function <em>f</em> there exists an integer <em>n</em> with <span><math><mi>ν</mi><mo>(</mo><mi>f</mi><mo>(</mo><mi>n</mi><mo>)</mo><mo>)</mo><mo>=</mo><mi>ν</mi><mo>(</mo><mi>n</mi><mo>)</mo></math></span>.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103523"},"PeriodicalIF":0.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strong reducibilities and set theory","authors":"Noah Schweber","doi":"10.1016/j.apal.2024.103522","DOIUrl":"10.1016/j.apal.2024.103522","url":null,"abstract":"<div><div>We study Medvedev reducibility in the context of set theory — specifically, forcing and large cardinal hypotheses. Answering a question of Hamkins and Li <span><span>[6]</span></span>, we show that the Medvedev degrees of countable ordinals are far from linearly ordered in multiple ways, our main result here being that there is a club of ordinals which is an antichain with respect to Medvedev reducibility. We then generalize these results to arbitrary “reasonably-definable” reducibilities, under appropriate set-theoretic hypotheses.</div><div>We then turn from ordinals to general structures. We show that some of the results above yield characterizations of counterexamples to Vaught's conjecture; another applies to all situations, assigning an ordinal to any reasonable class of structures and “measure” on that class. We end by discussing some directions for future research.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103522"},"PeriodicalIF":0.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dividing and forking in random hypergraphs","authors":"Hirotaka Kikyo , Akito Tsuboi","doi":"10.1016/j.apal.2024.103521","DOIUrl":"10.1016/j.apal.2024.103521","url":null,"abstract":"<div><div>We investigate the class of <em>m</em>-hypergraphs in which substructures with <em>l</em> elements have more than <em>s</em> subsets of size <em>m</em> that do not form a hyperedge. The class has a (unique) Fraïssé limit, if <span><math><mn>0</mn><mo>≤</mo><mi>s</mi><mo><</mo><mrow><mo>(</mo><mtable><mtr><mtd><mrow><mi>l</mi><mo>−</mo><mn>2</mn></mrow></mtd></mtr><mtr><mtd><mrow><mi>m</mi><mo>−</mo><mn>2</mn></mrow></mtd></mtr></mtable><mo>)</mo></mrow></math></span>. We show that the theory of the Fraïssé limit has <em>SU</em>-rank one if <span><math><mn>0</mn><mo>≤</mo><mi>s</mi><mo><</mo><mrow><mo>(</mo><mtable><mtr><mtd><mrow><mi>l</mi><mo>−</mo><mn>3</mn></mrow></mtd></mtr><mtr><mtd><mrow><mi>m</mi><mo>−</mo><mn>3</mn></mrow></mtd></mtr></mtable><mo>)</mo></mrow></math></span>, and dividing and forking will be different concepts in the theory if <span><math><mrow><mo>(</mo><mtable><mtr><mtd><mrow><mi>l</mi><mo>−</mo><mn>3</mn></mrow></mtd></mtr><mtr><mtd><mrow><mi>m</mi><mo>−</mo><mn>3</mn></mrow></mtd></mtr></mtable><mo>)</mo></mrow><mo>≤</mo><mi>s</mi><mo><</mo><mrow><mo>(</mo><mtable><mtr><mtd><mrow><mi>l</mi><mo>−</mo><mn>2</mn></mrow></mtd></mtr><mtr><mtd><mrow><mi>m</mi><mo>−</mo><mn>2</mn></mrow></mtd></mtr></mtable><mo>)</mo></mrow></math></span>.</div></div>","PeriodicalId":50762,"journal":{"name":"Annals of Pure and Applied Logic","volume":"176 2","pages":"Article 103521"},"PeriodicalIF":0.6,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}