Asymptotic equivalence of nonlinear and quasi linear differential equations with piecewise constant arguments

We consider nonlinear differential equations with piecewise constant arguments in the general case. This is based in the study of an equivalent integral equation, and in a solution of an integral inequality of Gronwall type. We establish the existence, uniqueness and the asymptotic behavior of the solutions of the equations. Equivalences, including unbounded solutions, with simpler equations are obtained.