On P(m)-ultrafilters on N
On points of qualitative semicontinuity
On Postian equations
On powers of Lindelöf spaces
We present a forcing construction of a Hausdorff zero-dimensional Lindelöf space whose square is again Lindelöf but its cube has a closed discrete subspace of size , hence the Lindelöf degree . In our model the Continuum Hypothesis holds true. After that we give a description of a forcing notion to get a space such that for all positive integers , but .
On practical problems with the explanation of the difference between possibility and probability
On Probability Function On Pseudo-Boolean Algebra
On probability of first order formulas in a given model
On problems of databases over a fixed infinite universe
In the relational model of databases a database state is thought of as a finite collection of relations between elements. For many applications it is convenient to pre-fix an infinite domain where the finite relations are going to be defined. Often, we also fix a set of domain functions and/or relations. These functions/relations are infinite by their nature. Some special problems arise if we use such an approach. In the paper we discuss some of the problems. We show that there exists a recursive...
On products of neat structures
On projection of nonseparable Souslin and Borel sets along separable spaces
On projectional skeletons in Vašák spaces
We provide an alternative proof of the theorem saying that any Vašák (or, weakly countably determined) Banach space admits a full -projectional skeleton. The proof is done with the use of the method of elementary submodels and is comparably simple as the proof given by W. Kubiś (2009) in case of weakly compactly generated spaces.
On properties of fuzzy left -ideals in hemirings with -norms.
On pseudo BE-algebras
In this paper, we introduce the notion of pseudo BE-algebra which is a generalization of BE-algebra. We define the concepts of pseudo subalgebras and pseudo filters and prove that, under some conditions, pseudo subalgebra can be a pseudo filter. We prove that every homomorphic image and pre-image of a pseudo filter is also a pseudo filter. Furthermore, the notion of pseudo upper sets in pseudo BE-algebras introduced and is proved that every pseudo filter is an union of pseudo upper sets.
On pseudo-bci ideals of pseudo-bci algebras
On pseudo-BCI-algebras
The notion of normal pseudo-BCI-algebras is studied and some characterizations of it are given. Extensions of pseudo-BCI-algebras are also considered.
On pseudocompactness and related notions in ZF
We study in ZF and in the class of spaces the web of implications/ non-implications between the notions of pseudocompactness, light compactness, countable compactness and some of their ZFC equivalents.
On pseudo-random sequences and their relation to a class of stochastical laws
On ()-fuzzy filters of pseudo-BL algebras.
On quantic conuclei in orthomodular lattices.
On quasi-antiorder in semigroups