在可数定向完备偏序集上引入了可数S-收敛网和拟可数S-收敛网的概念,基于此,分别给出了可数逼近偏序集和拟可数逼近偏序集的网式刻画。
In this paper, the countable S-convergence of nets and generalized countable S-convergence of nets on countably directed complete posers are introduced. Based on them, the characterizations of countably approximating posets by nets and generalized countably approximating posets by nets are given respectively.