On the existence of -primitives on arbitrary metric spaces
On the extension and generation of set-valued mappings of bounded variation
We study set-valued mappings of bounded variation of one real variable. First we prove the existence of an extension of a metric space valued mapping from a subset of the reals to the whole set of reals with preservation of properties of the initial mapping: total variation, Lipschitz constant or absolute continuity. Then we show that a set-valued mapping of bounded variation defined on an arbitrary subset of the reals admits a regular selection of bounded variation. We introduce a notion of generated...
On the extension of continuous functions
On the extensions of uniformly continuous mappings
On the extent of star countable spaces
For a topological property P, we say that a space X is star Pif for every open cover Uof the space X there exists Y ⊂ X such that St(Y,U) = X and Y has P. We consider star countable and star Lindelöf spaces establishing, among other things, that there exists first countable pseudocompact spaces which are not star Lindelöf. We also describe some classes of spaces in which star countability is equivalent to countable extent and show that a star countable space with a dense σ-compact subspace can have...
On the fixed points in an -limit set
Let and be closed subsets of [0,1] with a subset of the limit points of . Necessary and sufficient conditions are found for the existence of a continuous function such that is an -limit set for and is the set of fixed points of in .
On the Fréchet-Urysohn property in spaces of continuous functions
On the functionally countable subalgebra of C(X)
On the functor of order-preserving functionals
We introduce a functor of order-preserving functionals which contains some known functors as subfunctors. It is shown that this functor is weakly normal and generates a monad.
On the fundamental dimension of the Cartesian product of compacta with the fundamental dimension 2
On the generalized property
On the generalized retract method for differential inclusions with constraints.
On the Graphs which are the Edge of a Plane Tiling.
On the homotopy equivalence of the spaces of proper and local maps
We prove that for n > 1 the space of proper maps P 0(n, k) and the space of local maps F 0(n, k) are not homotopy equivalent.
On the hyperspaces of hereditarily indecomposable continua
On the ideal convergence of sequences of quasi-continuous functions
For any Borel ideal ℐ we describe the ℐ-Baire system generated by the family of quasi-continuous real-valued functions. We characterize the Borel ideals ℐ for which the ideal and ordinary Baire systems coincide.
On the insertion of Darboux functions
The main goal of this paper is to characterize the family of all functions f which satisfy the following condition: whenever g is a Darboux function and f < g on ℝ there is a Darboux function h such that f < h < g on ℝ.
On the intrinsic geometry of a unit vector field
We study the geometrical properties of a unit vector field on a Riemannian 2-manifold, considering the field as a local imbedding of the manifold into its tangent sphere bundle with the Sasaki metric. For the case of constant curvature , we give a description of the totally geodesic unit vector fields for and and prove a non-existence result for . We also found a family of vector fields on the hyperbolic 2-plane of curvature which generate foliations on with leaves of constant intrinsic...
On the inverse image of Baire spaces.
On the Lefschetz fixed point theorem for multivalued weighted mappings