sa t isfies jRn N is a suitably chosen int eger.
T hence , fl1 +r = di ;, for i = 1, ... , r, Ifl i I ::; 1 for i = 1, ... , 2r and t he corresponding eigenv ectors e; ) ( G,. and ( _ _ 1 1-d j J eJ for J, ce,) J = 1 , ... , r forj =l , .. , r (ej = j-t h unit vector) are linearly ind ependent. 26) is stable. 1 Definitions and Elementary Properties Let X be a metric space with metric d : X x X - t JR+ and let (fn)nEN be a sequence of cont inuous mappings f n : X - t X , n E N. Then the pair (X, (fn)n EN) is called a non-autonomous time-di scret e dynamical system .