Unicity theorems for entire functions concerning four small functions

Abstract

This paper studies the problem of uniqueness of entire functions concerning four small functions and shows that if two entire functions f and g satisfy \bar{E}(a_j, k, f)=\bar{E}(a_j, k, g) for j=1, 2, 3, 4, where a_j are four distinct small functions with respect to f and g, and k is a positive integer or ∞ with k≥8, then f≡g.