Almost periodic weak solutions of neutral delay-differential equations with piecewise constant argument

In this paper, we give some theorems on the almost periodic weak solutions of second-order neutral delay-differential equations with piecewise constant argument of the form(x(t)+px(t-1))″=qx2t+12+f(t),where [·][·] denotes the greatest integer function, p,qp,q are nonzero constants, and f(t)f(t) is almost periodic.