若干类线性正算子的Λ＿ω（A）类保持性质

ON THE PROPERTY OF SOME LINEAR POSITIVE OPERATORS PRESERVING THE CLASS Λ_ω(A)

设ω（ｘ）是区间Ｉ上的上凸连续模函数，记Λ＿ω（Ａ）＝｛ｆ∈Ｃ（Ｉ）：ω（ｆ，ｘ）≤Ａω（ｘ）｝，文章得到了ｆ∈Λ＿ω（Ａ）的充要条件是Ｌ＿ｎｆ∈Λ＿ω（Ａ），其中Ｌ＿ｎ是相当广泛的若干类线性正算子．

Let ω(x)be any concave modulus of continuity and Λ_ω(A)={f∈C(I) : ω(f,x)≤A_ω(x)} The following results are obtained:Therorem: Where Ln is some linear positive operators.