Normal families of meromorphic functions concerning shared values

In this paper we study the problem of normal families of meromorphic functions concerning shared values and prove that a family F of meromorphic functions in a domain D is normal if for each pair of functions f and g in F, f − af n and g − agn share a value b in D where n is a positive integer and a, b are two finite constants such that n 4 and a = 0. This result is not true when n 3. © 2007 Elsevier Inc. All rights reserved.