content_image/306431.jpg content_image/306430.jpg content_image/306429.jpg content_image/306428.jpg content_image/306427.jpg content_image/306426.jpg content_image/306425.jpg
Hence, it can be deduced by means of (4.7) and (4.8) that 

<img src='content_image/306431.jpg'>

Now, by using the equation 

we attain that 

<img src='content_image/306430.jpg'>

<img src='content_image/306429.jpg'>

The last inequality implies that 

Therefore, for each n ∈ N , there exists a number ζ$_{n}$ ∈ [ − Δ , Δ] such that 

Let us define the number 

<img src='content_image/306428.jpg'>

<img src='content_image/306427.jpg'>

<img src='content_image/306426.jpg'>

and denote ˜ τ$_{n}$ = τ$_{n}$ + ζ$_{n}$, n ∈ N . Clearly, ˜ τ$_{n}$ → ∞ as n → ∞ . One can confirm for − Δ ≤ s ≤ Δ that 

<img src='content_image/306425.jpg'>

