引入了网族及预收敛类的概念,给出了从T(X)(即X上的预拓扑的全体)到S(X)(即X上的预收敛类的全体)的单射,证明了当X是有限集时该映射是双射.
The notions of family of nets and pre-convergence class are introduced and an injection F from T(X) (the set of all pre-topologies on X) to S(X) (the set of all pre-convergence classes of families of nets) is given. It is proved that F is a bijecfion if X is a finite set.