Normal families of meromorphic functions with multiple zeros

摘要

Let F be a family of meromorphic functions defined in a domain D such that for each f∈F, all zeros of f(z) are of multiplicity at least 3, and all zeros of f'(z) are of multiplicity at least 2 in D. If for each f∈F, f'(z)-1 has at most 1 zero in D, ignoring multiplicity, then F is normal in D.