In this paper, we describe the properties of entire solutions of a nonlinear differential-difference equation and a Fermat type equation, and improve several previous theorems greatly. In addition, we also deduce a uniqueness result for an entire function f(z) that shares a set with its shift [Formula: see text], which is a generalization of a result of Liu.

1. Differential-Difference Equations Dating back to the work of Fermi, Pasta, and Ulam in the 1950’s [2] differential-difference equations (DDEs) have been the focus of many nonlinear studies. A number of physically interesting problems can be modeled with nonlinear DDEs, including particle vibrations in lattices, currents in electrical networks, pulses in biological chains, etc. DDEs play impo...