“…where x ∈ R, τ i > 0, τ i ∈ R, H(.) = H(t, x(t), x [2] (t), ..., x [n] (t)), x [n] (t) is the iterative term and stands for x composed with itself n times, for example, x [2] (t) = x(x(t)), c i ∈ C([0, T ], (0, 1)), a ∈ C(R, (0, ∞)), and f ∈ C([0, T ] × R 2 , (0, ∞)) and H ∈ C([0, T ] × R n , (0, ∞)) are periodic functions, i.e., c i (t + T ) = c i (t), a(t + T ) = a(t), f i (t + T, x(t), x(t − τ i )) = f i (t, x(t), x(t − τ i )) and H(t + T, x(t), x [2] (t), ..., x [n] (t)) = H(t, x(t), x [2] (t), ..., x [n] (t)). Furthermore, we presume that the functions f i and H(...) satisfy the Lipschitz condition in their respective arguments;…”