Let X be a metric continuum and let 2(superscript X) and C (X) denote the hyperspaces of subcontioua and of closed subset of X, respectively, F1(X) is 1-fold symmetric product of X.

• 摘要给定连续统X,2(上标X),C(X)，分别表示X的闭子集和子连续统的超空间，F1(X)是X的一重对称积空间。