“…For fixed z, this series converges uniformly in x ∈ [−1, 1] (see, e.g., [26, Chapter IX, Theorem 9.1.1]) and as shown in [5], it is valid for a set of parameters λ, γ, β containing R * + ×(−1, ∞) 2 . However, we shall restrict ourselves to the latter which is sufficient for our purposes and subsequent computations.…”