Some Equivalent Conditions of Semi-coutinuous Functions on Topological Space

In this paper,definitions of upper and lower limits for net and the one for function on topological space are given first,and the definition of semi-coutinuous function from topological space to ordered linear ordered topological space is given.Then,the relationship between coutinuous function and semi-coutinuous function on topological space is obtained.At last,some equivalent conditions of semi-coutinuous function on topological space is proved.