Mass media have completely changed the way politicians and voters communicate. Communication within political parties, membership activism, party discipline respect for hierarchy become less important, because play a central role in dissemination of information, education, also process persuading masses to do certain things. According Zoran Slavujević (2009), contemporary politics is actually a...

In this paper we consider bi-Cohen-Macaulay graphs, and give a complete classification of such graphs in the case they are bipartite or chordal. General biCohen-Macaulay graphs are classified up to separation. The inseparable bi-CohenMacaulay graphs are determined. We establish a bijection between the set of all trees and the set of inseparable bi-Cohen-Macaulay graphs.

Assuming the continuum hypothesis there is an inseparable sequence of length ω1 that contains no Lusin subsequence, while if Martin’s Axiom and ¬CH is assumed then every inseparable sequence (of length ω1) is a union of countably many Lusin subsequences. 2000 Mathematics Subject Classification . 03E05 (Combinatorial set theory), 03E50 (Continuum hypothesis and Martin’s axiom), 03E35 ( Consisten...