Estimates for solutions to a class of nonautonomous systems of neutral type with unbounded delay

Under consideration is the class of nonlinear systems of nonautonomous differential equations of neutral type with a variable delay that can be unbounded. Using a Lyapunov–Krasovskii functional, we establish some estimates of solutions that allow us to conclude whether the solutions are stable. In the case of exponential and asymptotic stability, we estimate the attraction domains and the rate of stabilization of solutions at infinity.