“…Descriptor (singular) linear systems were investigated by Cuihong (2012), Dodig and Stosic (2009), Dai (1989), Duan (2010), Fahmy and O'Reill (1989), Gantmacher (1959), Kaczorek (2012b;2004;1992;2012a), Kucera and Zagalak (1988), Lewis (1983), Luenberger (1977;1978), Sajewski (2016), Van Dooren (1979) or Virnik (2008), and the positivity and stability of fractional descriptor time-varying discrete-time linear by Kaczorek (2016c), who also addressed the eigenvalues and invariants assignment by state and input feedbacks (Kaczorek, 2004;1992;2011b). The computation of Kronecker's canonical form of a singular pencil was analyzed by Van Dooren (1979).…”