2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77859For linear evolution control system described by $\dot{x}=Ax(t)+Bu(t),x(0)=x_{0}$ ($A$ generates a strongly continuous semigroup ${S(t)}_{t\ge 0}$ in a Banach space $X$; $B$ is a linear unbounded operator), the attainable set $K(t)$ is studied. Conditions of the independence of $t$ for its closure $\bar{K(t)}$ are established. Controllability conditions for some classes of evolution systems are obtained.19 pages, LaTeX, no figuresDynamical Systems35R30 (Primary) 35J20, 65M30 (Secondary)text