Differential Polynomials Of Meromorphic Functions Of Exceptions Set And Derivative Deficiency

Since Lehto, 0. presented the concept of exceptional set of entire functions and meromorphic functions, many famous scholars have studied on it , and achieved lot. Anderson ,Baker and Clunie put forward the problem of exceptional set of differential polynomials, which is solved completely for entire functions in this article; besides, the author makes great progress in research of meromorphic functions.The estimate of deficiency sum of mereomorphic derivatives is an important study field in value distribution theory of meromorphic functions. This article does a lot on Mues?s and Drasin ?s guess of precise estimate of deficiency sum of meromorphic functions and its derivatives, Ozawa?s research of d?s accurate value concerned with deficiency sum of meromorphic derivatives and k( A) ,precise estimate on deficiency sum of linear independent functions, and improves the results given by famous experts Yang Lo et al.This article consists of four parts. Part I is introduction , introducing mainly the study barkground, basic definitions and signs of the value distribution of meromorphic functions. Part II discusses the exceptional set of differential polynomials in entire functions. Part Ill is devoted to the discussion of the exceptional set of differential polynomials in meromor?phic functions. Part iv deals with deficiency sum meromorphic devivatives.