“…Let b∈ (0, 1], ω ∈ C([0, b]; R), ω(α) ≥ 0 at α ∈ [0, b), ω(b) > 0, the spectrum σ(Λ 1 ) do not contain the origin and zeros of the polynomial P n (λ), u 0 ∈ D M . Then, there exists a unique solution of problem (16)-(18). From the proof of Lemma 6, it follows that we can obtain the analogous result for a case b ∈ (1, 2], if we provide the positivity of the value min k∈N,Reλ>a…”