Normality of meromorphic functions concerning sharing values

摘要

Let n, k be positive integers satisfying n ≥ 2k + 4, a ≠ 0 be a complex number, and let F be a family of functions meromorphic in a domain D, if for each f ∈ F , f~n + af~((k)) and g~n + ag~((k)) share b, and all zeros have multiplicity at least k + 1, then F is normal in D.