Dependences between definitions of finiteness
Dependences between definitions of finiteness. II
Der Beweis eines Satzes von G. Choodnovsky.
Derived operations in Goguen categories.
Descriptive Kakutani equivalence
Descriptive properties of density preserving autohomeomorphisms of the unit interval
We prove that density preserving homeomorphisms form a Π11-complete subset in the Polish space ℍ of all increasing autohomeomorphisms of unit interval.
Descriptive set theoretical complexity of randomness notions
We study the descriptive set theoretical complexity of various randomness notions.
Descriptive Set Theory and Infinitary Languages
Descriptive set-theoretical properties of an abstract density operator
Let (ℝ) stand for the hyperspace of all nonempty compact sets on the real line and let d ±(x;E) denote the (right- or left-hand) Lebesgue density of a measurable set E ⊂ ℝ at a point x∈ ℝ. In [3] it was proved that is ⊓11-complete. In this paper we define an abstract density operator ⅅ± and we generalize the above result. Some applications are included.
Destroying precaliber : an application of a Δ-systems lemma for closed sets
Determinacy of adversarial Gowers games
We prove a game-theoretic dichotomy for sets of block sequences in vector spaces that extends, on the one hand, the block Ramsey theorem of W. T. Gowers proved for analytic sets of block sequences and, on the other hand, M. Davis’ proof of Σ⁰₃ determinacy.
Determinateness in the low protective hierarchy
Détermination des jeux boréliens et problèmes logiques associés
Deux relations dénombrables, logiquement équivalentes pour le second ordre, sont isomorphes
DFIS: A novel data filling approach for an incomplete soft set
The research on incomplete soft sets is an integral part of the research on soft sets and has been initiated recently. However, the existing approach for dealing with incomplete soft sets is only applicable to decision making and has low forecasting accuracy. In order to solve these problems, in this paper we propose a novel data filling approach for incomplete soft sets. The missing data are filled in terms of the association degree between the parameters when a stronger association exists between...
Diamond and λ-systems
Dichotomies pour les espaces de suites réelles
There is a general conjecture, the dichotomy (C) about Borel equivalence relations E: (i) E is Borel reducible to the equivalence relation where X is a Polish space, and a Polish group acting continuously on X; or (ii) a canonical relation is Borel reducible to E. (C) is only proved for special cases as in [So]. In this paper we make a contribution to the study of (C): a stronger conjecture is true for hereditary subspaces of the Polish space of real sequences, i.e., subspaces such that ...
Die Axiomatisierung der Mengenlehre
Die Cantorsche Abbildung ist ein Borel-Isomorphismus.
Die Nichtaxiomatisierbarkeit der unendlichwertigen Mengenlehre.