“…Consequently, the key to our success is the formulation of the Lemmas 4.4,4.5 and Propositions 3.2,4.1, 4.2, 4.6, without which it is hardly ever possible to establish any duality to the problem with second order DSIs and DFIs. To the best of our knowledge, there are a few papers (see [9], [16], [17], [25] and references therein) devoted to duality problems of first order DFIs. Building on these results, we then treat dual results according to the dual operations of addition and infimal convolution of convex functions [1], [9], [11], [14], [15].…”