Finally we use obtained normal form and universal unfolding to discuss codimension 3 degenerate bifurcations of nonlinear dynamical system.

This paper reveals that the group velocity of a weak laser probe field can be manipulated by controlling the intensity of the driving field applied to a near-degenerate closed three-level V system.

So, it has a practical significance to study the character of solutions of either degenerate differential system with delay or impulsive differential equations with delays.