A necessary and sufficient condition for the oscillation of first order linear difference equations with several delay arguments

In this article, we discuss the oscillation of all solutions of a first order linear delay difference equation with several delay arguments and obtain some new oscillation criteria under more relaxed conditions. In particular, we establish a necessary and sufficient condition only based on the coefficient functions and delay arguments when the coefficient functions are non-negative. Examples and tables are given to illustrate our results. (C) 2019 Elsevier Inc. All rights reserved.