Borsuk-Ulam type theorems
A generalization of the theorem of Bajmóczy and Bárány which in turn is a common generalization of Borsuk's and Radon's theorem is presented. A related conjecture is formulated.
Estimation of cut-vertices in edge-coloured complete graphs
Equivalent definitions for the measurability of a multivariate function and Filippov's lemma
From the text: "In the many papers in which the concept of measurability of a multivariate function arises, the authors usually formulate one definition of measurability and ignore its connections with other definitions. Assuming that the space, in which the values of the multivariate function lie, which admits only a closed set, is metric and compact we prove that all well-known definitions of measurability of multivariate functions are equivalent. "A. F. Filippov's lemma was first formulated in...
Combinatorial lemmas for polyhedrons
We formulate general boundary conditions for a labelling to assure the existence of a balanced n-simplex in a triangulated polyhedron. Furthermore we prove a Knaster-Kuratowski-Mazurkiewicz type theorem for polyhedrons and generalize some theorems of Ichiishi and Idzik. We also formulate a necessary condition for a continuous function defined on a polyhedron to be an onto function.
Combinatorial lemmas for polyhedrons I
We formulate general boundary conditions for a labelling of vertices of a triangulation of a polyhedron by vectors to assure the existence of a balanced simplex. The condition is not for each vertex separately, but for a set of vertices of each boundary simplex. This allows us to formulate a theorem, which is more general than the Sperner lemma and theorems of Shapley; Idzik and Junosza-Szaniawski; van der Laan, Talman and Yang. A generalization of the Poincaré-Miranda theorem is also derived.
Fixed simplex property for retractable complexes.
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