“…These are works on stabilization of an object with delay [1][2][3][4][5], stabilization of a group of objects by a single controller [6], assignment of a given finite spectrum [7][8][9], spectral reducibility [10][11][12], i.e., reduction of systems to a finite (but not given) spectrum, modal controllability [13][14][15][16][17]. At present, for retarded and neutral type systems, as well as for completely regular differential-algebraic systems with several delays, spectral criteria of modal controllability have been obtained [13,15,16] that coincide in form with the criterion of complete controllability (see, for example, [18]). They are also solvability conditions for the problem of assigning a finite spectrum [7,9].…”