Jin Fa CHEN(1),Z. ANNIE(2)
Abstract In this article, we study the mth order neutral functional difference equations of mixed type: Am (xn + cxn-h + c*xn+h*) = k(qxn∧g + pxn+g*), k =±1. Where c,c*,p,q are real numbers and h,h*,g and g* are positive integer, and establish some new criteria for the oscillation of such equations. Our results in this paper improve on all theorems in [1], and answer an open problem offered by Grace S. R. in [1].