Normal families related to shared sets

摘要

We studied the normality criterion for families of meromorphic functions related to shared sets.Let F be a family of meromorphic functions on the unit disc Δ,a and b be distinct non-zero values,S={a,b},and k be a positive integer.If for every f∈F,i) the zeros of f(z) have a multiplicity of at least k+1,and ii) f(k)(S)■f(S),then F is normal on Δ.At the same time,the corresponding results of normal function are also proved.