给出连续线性算子的值域闭性的一个一般性定理并说明其应用.特别地,说明它是半Fredholm算子性质定理和Kato定理的推广.
Gives a general theorem of closeness of continuous linear operator ranges and illustrates its appilcations. Particulary, illustrates that it is a generalization of Kato theorem and property theorem of semi-Freholm operators.