Convergence in the Boundary Layer for Nonhomogeneous Linear Singularly   Perturbed Systems
  Convergence of the solutions of nonhomogeneous linear singularly perturbed systems to that of the corresponding reduced singular system on the half-line [0, $\infty $) is considered. To include the situation on a neighborhood of initial instant, a boundary layer, a distributional approach to convergence is adopted. An explicit analytical expression for the limit as a distribution is proved. 
Zhibin Yan