  The main objective of this article is to develop a matrix pencil approach for
the study of the controllability and reachability of a class of linear singular
discrete time systems. The description equation of a practical system may be
established through selection of the proper state variables. Time domain
analysis is the method of analyzing the system based on this description
equation, through which we may gain a fair understanding of the system's
structural features as well as its internal properties. Using time domain
analysis, this article studies the fundamentals in system theory such as
reachability and controllability.
