ABSTRACT
A. It has been shown in the Introduction that various real world prob lems are modelled by difference equations describing the evolution of sequences of numbers that represent physical quantities (signals). In the linear case and when the only motor of the dynamics is given by internal phenomena incorporated in the initial state, the model is the autonomous linear difference system with constant coefficients
where x is a n-dimensional state vector, A a, n x n constant matrix and t - the integer independent variable - conventionally called "tim e”, although it might sometimes represent the numbering of sequence elements.
