“…for a one dimensional telegraph equation with involution and Neumann conditions was studied in paper [25]. Assume that all compatibility conditions for the given smooth data ifunctions F(τ, iη), a(η), (η), χ(η), ξ(τ), G(η) are fulfilled, that G (−b) = G (b) = 0 and a ≥ a(η) = a(−η) ≥ δ > 0, β > 0, δ − a|γ| ≥ 0,, and that b −b G(y)dy = 0.…”