138 citations
- Polish Academy of SciencesPL73 papers
- Institute of PhysicsPL33 papers
- Center for Theoretical PhysicsPL29 papers
- University of WarsawPL24 papers
- Institute of MathematicsPL11 papers
- Centre National de la Recherche ScientifiqueFR9 papers
- Czech Academy of SciencesCZ9 papers
- Czech Academy of Sciences, Institute of MathematicsCZ9 papers
- Leipzig UniversityDE9 papers
- Institute of High Pressure PhysicsPL8 papers
- Centrum Badań KosmicznychPL7 papers
- Commissariat à l'Énergie Atomique et aux Énergies AlternativesFR7 papers
18 papers · 1 filter
One Henkin Quantifier in the empty vocabulary suffices for undecidability
Konrad Zdanowski
We prove that there are single Henkin quantifiers such that first order logic augmented by one of these quantifiers is undecidable in the empty vocabulary. Examples of such quantif…
On non-archimedean Gurarii spaces
Jerzy Kcakol, Wiesław Kubiś, Albert Kubzdela
Let be the class of all non-archimedean finite-dimensional Banach spaces. A non-archimedean Gurarii Banach space over a non-archimedean valued field is constructe…
A generalization of -metrizable spaces
Andrzej Kucharski, Sławomir Turek
We introduce a new class of -metrizable spaces, namely countably -metrizable spaces. We show that the class of all -metrizable spaces is a proper s…
A Dirichlet type problem for complex polyharmonic functions
Hubert Grzebuła, Sławomir Michalik
We extend holomorphically polyharmonic functions on a real ball to a complex set being the union of rotated balls. We solve a Dirichlet type problem for complex polyharmonic functi…
On the Mints Hierarchy in First-Order Intuitionistic Logic
Aleksy Schubert, Paweł Urzyczyn, Konrad Zdanowski
We stratify intuitionistic first-order logic over into fragments determined by the alternation of positive and negative occurrences of quantifiers (Mints hierarchy)…
On the class of perfectly null sets and its transitive version
Michał Korch, Tomasz Weiss
We introduce two new classes of special subsets of the real line: the class of perfectly null sets and the class of sets which are perfectly null in the transitive sense. These cla…