Shuffle-invariant total orders.
Solution of a combinatorially formulated monodromy problem of Eisenbud and Harris
Some classes of idempotent functions and their compositions
Some general classes of comatching graphs.
Some new facts about group 𝒢 generated by the family of convergent permutations
The aim of this paper is to present some new and essential facts about group 𝒢 generated by the family of convergent permutations, i.e. the permutations on ℕ preserving the convergence of series of real terms. We prove that there exist permutations preserving the sum of series which do not belong to 𝒢. Additionally, we show that there exists a family G (possessing the cardinality equal to continuum) of groups of permutations on ℕ such that each one of these groups is different than 𝒢 and is composed...
Some observations and solutions to short and long global Nim.
Strong sequences and the weight of regular spaces
It will be shown that if in a family of sets there exists a strong sequence of the length then this family contains a subfamily consisting of pairwise disjoint sets. The method of strong sequences will be used for estimating the weight of regular spaces.
Strong sequences, binary families and Esenin-Volpin's theorem
One of the most important and well known theorem in the class of dyadic spaces is Esenin-Volpin's theorem of weight of dyadic spaces. The aim of this paper is to prove Esenin-Volpin's theorem in general form in class of thick spaces which possesses special subbases.
Suites infinies à répétitions bornées.
Sur un problème d'ordre lié à la permutation de variables