“…The conditions of the Theorem 3 hold provided that ℓ 0 = e − 1, k = 1, a = a(t) = ℓ 0 t. Then, we can have ρ ∈ (0, 0.2909883534). Then, the definition of the derivative according to Fréchet [1,8,11,27,30] is given below for the operator E E ′ (z(w))(ξ) = w(ξ) − 18 1 0 ξτz(τ) 2 w(τ)dτ for each w ∈ K[0, 1]. Therefore, the conditions are validated, since for x * = 0, E ′ (x * (ξ)) = I provided that ℓ 0 = 9, a = a(t) = ℓ 0 t, and k = 1.…”