Mathematica Eterna
Open Access

Abstract

On inequalities among some cardinal invariants

Joanna Jureczko

The strong sequences method was introduced by B. A. Efimov, as a useful method for proving famous theorems in dyadic spaces: Marczewski theorem on cellularity, Shanin theorem on a calibre and EseninVolpin theorem. In this paper there will be considered strong sequences on a set with arbitrary relation as generalization of a partially ordered set. In this paper there will be introduced a new cardinal invariant slength of the strong sequence and investigated relations among s and other well known invariants like: saturation, boundeness, density, calibre.