“…Then, Mellin moments of the parton distributions and structure functions (SFs), which are essential in testing sum rules, are obtained as integrals of the distribution or structure functions over the Bjorken-x variable. An alternative approach, in which one can study directly the evolution of the truncated moments of the parton distributions was proposed in [6], [7], [8], [9]. Later on, we elaborated the exact evolution equations for the truncated moments of the parton densities and structure functions [10], [11], [12].…”