Oscillatory properties of solutions of three-dimensional differential systems of neutral type

Abstract

The purpose of this paper is to obtain oscillation criteria for the differential system

$$\begin{gathered} \left[ {y_{\text{1}} \left( t \right) - a\left( t \right)y_{\text{1}} \left( {g\left( t \right)} \right)} \right]^\prime = p\left( t \right)f_1 \left( {y_{\text{2}} \left( {h_2 \left( t \right)} \right)} \right) \hfill \\ {\text{ }}y_2^\prime \left( t \right) = p\left( t \right)f_2 \left( {y_{\text{3}} \left( {h_3 \left( t \right)} \right)} \right) \hfill \\ {\text{ }}y_{\text{3}}^\prime \left( t \right) = - p_3 \left( t \right)f_3 \left( {y_{\text{1}} \left( {h_1 \left( t \right)} \right)} \right),{\text{ }}t \in \mathbb{R}_ + = \left[ {0,\infty } \right) \hfill \\ \end{gathered} $$