Keywords: به طور متوالی جمع و جور; 54H11; 22A05; 54A20; 54E45; 54D55; 54E20; 54D05Topological group; Quotient group; Three space property; Extension of a group; Sequentially compact; Sequential; Fréchet; First-countable; Second-countable; Metrizable; cs-Network; k-Network; Locally compact;