主要证明了:设k≥2是一个正整数,M是一个正数,c是一个非零有穷复数.F是区域D内的一族亚纯函数,其中每个函数的零点的重数至少是k.若对于F中的任意函数f,f(z)=0 f(k)(z)=0,f(k)(z)=c |f(k+1)(z)|≤M,则F在D内正规,其中c≠0是必需的.
It is mainly proved: let k ≥ 2 be a positive integer, M a positive number,let c (≠ 0) be a finite value, and let F be a family of meromorphic functions in a domain D, all of whose zeros are of multiplicity k at least. If, for each function f ∈F,f(z) = 0 f(k)(z) = 0, f(k)(z) = c =〉 |f(k+1)(z)| 〈 M, then F is normal in D. And c ≠ 0 is necessary.