| In 1948,F,B,Jones defined the set function T and gave some relative conclusions. Since then,many people have been studying it, Sergio Maci(?)s's studies are the most remarkable among them.In recent years,with the need of developing and riching the continua, more eyes rely on other functions,such as,the set functionR,the set functionK. Although the definitions of these set functions are different,they have many similar properties and conclusions.This paper is about the fun set function R,its main conclusions are the following: (1)If X is an arcwise connected continuum, thenR.((?)) = (?) ;(2)Let X and Y be hereditarily unicoherent and arcwise connected continua,and let/ : X (?) Y be a closed surjcctive map.If A,B∈2~x,then the following hold:... |
