{"title":"Positively closed parametrized models","authors":"Kristóf Kanalas","doi":"arxiv-2409.11231","DOIUrl":"https://doi.org/arxiv-2409.11231","url":null,"abstract":"We study positively closed and strongly positively closed $mathcal{C}to\u0000Sh(B)$ models, where $mathcal{C}$ is a $(kappa ,kappa )$-coherent category\u0000and $B$ is a $(kappa ,kappa )$-coherent Boolean-algebra for some weakly\u0000compact $kappa $. We prove that if $mathcal{C}$ is coherent and $X$ is a\u0000Stone-space then positively closed, not strongly positively closed\u0000$mathcal{C}to Sh(X)$ models may exist.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Denotational semantics driven simplicial homology?","authors":"Davide Barbarossa","doi":"arxiv-2409.11566","DOIUrl":"https://doi.org/arxiv-2409.11566","url":null,"abstract":"We look at the proofs of a fragment of Linear Logic as a whole: in fact,\u0000Linear Logic's coherent semantics interprets the proofs of a given formula $A$\u0000as faces of an abstract simplicial complex, thus allowing us to see the set of\u0000the (interpretations of the) proofs of $A$ as a geometrical space, not just a\u0000set. This point of view has never been really investigated. For a ``webbed''\u0000denotational semantics -- say the relational one --, it suffices to down-close\u0000the set of (the interpretations of the) proofs of $A$ in order to give rise to\u0000an abstract simplicial complex whose faces do correspond to proofs of $A$.\u0000Since this space comes triangulated by construction, a natural geometrical\u0000property to consider is its homology. However, we immediately stumble on a\u0000problem: if we want the homology to be invariant w.r.t. to some notion of\u0000type-isomorphism, we are naturally led to consider the homology functor acting,\u0000at the level of morphisms, on ``simplicial relations'' rather than simplicial\u0000maps as one does in topology. The task of defining the homology functor on this\u0000modified category can be achieved by considering a very simple monad, which is\u0000almost the same as the power-set monad; but, doing so, we end up considering\u0000not anymore the homology of the original space, but rather of its\u0000transformation under the action of the monad. Does this transformation keep the\u0000homology invariant ? Is this transformation meaningful from a geometrical or\u0000logical/computational point of view ?","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AC and the Independence of WO in Second-Order Henkin Logic, Part II","authors":"Christine Gaßner","doi":"arxiv-2409.11126","DOIUrl":"https://doi.org/arxiv-2409.11126","url":null,"abstract":"This article concerns with the Axiom of Choice (AC) and the well-ordering\u0000theorem (WO) in second-order predicate logic with Henkin interpretation (HPL).\u0000We consider a principle of choice introduced by Wilhelm Ackermann (1935) and\u0000discussed also by David Hilbert and Ackermann (1938), by G\"unter Asser (1981),\u0000and by Benjamin Siskind, Paolo Mancosu, and Stewart Shapiro (2020). Our\u0000discussion is restricted to so-called Henkin-Asser structures of second order.\u0000Here, we give the technical details of our proof of the independence of WO from\u0000the so-called Ackermann axioms in HPL presented at the Colloquium Logicum in\u00002022. Most of the definitions used here can be found in Sections 1, 2, and 3 in\u0000Part I.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Neostability transfers in derivation-like theories","authors":"Omar Leon Sanchez, Shezad Mohamed","doi":"arxiv-2409.11248","DOIUrl":"https://doi.org/arxiv-2409.11248","url":null,"abstract":"Motivated by structural properties of differential field extensions, we\u0000introduce the notion of a theory $T$ being derivation-like with respect to\u0000another model-complete theory $T_0$. We prove that when $T$ admits a\u0000model-companion $T_+$, then several model-theoretic properties transfer from\u0000$T_0$ to $T_+$. These properties include completeness, quantifier-elimination,\u0000stability, simplicity, and NSOP$_1$. We also observe that, aside from the\u0000theory of differential fields, examples of derivation-like theories are\u0000plentiful.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amirhossein Akbar Tabatabai, Majid Alizadeh, Masoud Memarzadeh
{"title":"On a Generalization of Heyting Algebras II","authors":"Amirhossein Akbar Tabatabai, Majid Alizadeh, Masoud Memarzadeh","doi":"arxiv-2409.10642","DOIUrl":"https://doi.org/arxiv-2409.10642","url":null,"abstract":"A $nabla$-algebra is a natural generalization of a Heyting algebra, unifying\u0000several algebraic structures, including bounded lattices, Heyting algebras,\u0000temporal Heyting algebras, and the algebraic representation of dynamic\u0000topological systems. In the prequel to this paper [3], we explored the\u0000algebraic properties of various varieties of $nabla$-algebras, their\u0000subdirectly-irreducible and simple elements, their closure under\u0000Dedekind-MacNeille completion, and their Kripke-style representation. In this sequel, we first introduce $nabla$-spaces as a common generalization\u0000of Priestley and Esakia spaces, through which we develop a duality theory for\u0000certain categories of $nabla$-algebras. Then, we reframe these dualities in\u0000terms of spectral spaces and provide an algebraic characterization of natural\u0000families of dynamic topological systems over Priestley, Esakia, and spectral\u0000spaces. Additionally, we present a ring-theoretic representation for some\u0000families of $nabla$-algebras. Finally, we introduce several logical systems to\u0000capture different varieties of $nabla$-algebras, offering their algebraic,\u0000Kripke, topological, and ring-theoretic semantics, and establish a deductive\u0000interpolation theorem for some of these systems.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tameness Properties in Multiplicative Valued Difference Fields with Lift and Section","authors":"Christoph Kesting","doi":"arxiv-2409.10406","DOIUrl":"https://doi.org/arxiv-2409.10406","url":null,"abstract":"We prove relative quantifier elimination for Pal's multiplicative valued\u0000difference fields with an added lifting map of the residue field. Furthermore,\u0000we generalize a $mathrm{NIP}$ transfer result for valued fields by Jahnke and\u0000Simon to $mathrm{NTP}_2$ to show that said valued difference fields are\u0000$mathrm{NTP}_2$ if and only if value group and residue field are.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transfer principles for forking and dividing in expansions of pure short exact sequences of Abelian groups","authors":"Akash Hossain","doi":"arxiv-2409.10148","DOIUrl":"https://doi.org/arxiv-2409.10148","url":null,"abstract":"In their article about distality in valued fields, Aschenbrenner, Chernikov,\u0000Gehret and Ziegler proved resplendent Ax-Kochen-Ershov principles for\u0000quantifier elimination in pure short exact sequences of Abelian structures. We\u0000study how their work relates to forking, and we prove Ax-Kochen-Ershov\u0000principles for forking and dividing in this setting.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hyperformalism for Bunched Natural Deduction Systems","authors":"Shay Allen Logan, Blane Worley","doi":"arxiv-2409.10418","DOIUrl":"https://doi.org/arxiv-2409.10418","url":null,"abstract":"Logics closed under classes of substitutions broader than class of uniform\u0000substitutions are known as hyperformal logics. This paper extends known results\u0000about hyperformal logics in two ways. First: we examine a very powerful form of\u0000hyperformalism that tracks, for bunched natural deduction systems, essentially\u0000all the intensional content that can possibly be tracked. We demonstrate that,\u0000after a few tweaks, the well-known relevant logic $mathbf{B}$ exhibits this\u0000form of hyperformalism. Second: we demonstrate that not only can hyperformalism\u0000be extended along these lines, it can also be extended to accommodate not just\u0000what is proved in a given logic but the proofs themselves. Altogether, the\u0000paper demonstrates that the space of possibilities for the study of\u0000hyperformalism is much larger than might have been expected.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Directed equality with dinaturality","authors":"Andrea Laretto, Fosco Loregian, Niccolò Veltri","doi":"arxiv-2409.10237","DOIUrl":"https://doi.org/arxiv-2409.10237","url":null,"abstract":"We show how dinaturality plays a central role in the interpretation of\u0000directed type theory where types are interpreted as (1-)categories and directed\u0000equality is represented by $hom$-functors. We present a general elimination\u0000principle based on dinaturality for directed equality which very closely\u0000resembles the $J$-rule used in Martin-L\"of type theory, and we highlight which\u0000syntactical restrictions are needed to interpret this rule in the context of\u0000directed equality. We then use these rules to characterize directed equality as\u0000a left relative adjoint to a functor between (para)categories of dinatural\u0000transformations which contracts together two variables appearing naturally with\u0000a single dinatural one, with the relative functor imposing the syntactic\u0000restrictions needed. We then argue that the quantifiers of such a directed type\u0000theory should be interpreted as ends and coends, which dinaturality allows us\u0000to present in adjoint-like correspondences to a weakening functor. Using these\u0000rules we give a formal interpretation to Yoneda reductions and (co)end\u0000calculus, and we use logical derivations to prove the Fubini rule for\u0000quantifier exchange, the adjointness property of Kan extensions via (co)ends,\u0000exponential objects of presheaves, and the (co)Yoneda lemma. We show\u0000transitivity (composition), congruence (functoriality), and transport\u0000(coYoneda) for directed equality by closely following the same approach of\u0000Martin-L\"of type theory, with the notable exception of symmetry. We formalize\u0000our main theorems in Agda.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AC and the Independence of WO in Second-Order Henkin Logic, Part I","authors":"Christine Gaßner","doi":"arxiv-2409.10276","DOIUrl":"https://doi.org/arxiv-2409.10276","url":null,"abstract":"This article concerns with the Axiom of Choice (AC) and the well-ordering\u0000theorem (WO) in second-order predicate logic with Henkin interpretation (HPL).\u0000We consider a principle of choice introduced by Wilhelm Ackermann (1935) and\u0000discussed also by David Hilbert and Ackermann (1938), by G\"unter Asser (1981),\u0000and by Benjamin Siskind, Paolo Mancosu, and Stewart Shapiro (2020). The\u0000discussion is restricted to so-called Henkin-Asser structures of second order.\u0000The language used is a many-sorted first-order language with identity. In\u0000particular, we give some of the technical details for a proof of the\u0000independence of WO from the so-called Ackermann axioms in HPL presented at the\u0000Colloquium Logicum in 2022.","PeriodicalId":501306,"journal":{"name":"arXiv - MATH - Logic","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}