“…However, it is worth notting that the obtained sub-and supersolution are quite different from the functions considered in the quoted papers, especially those constructed in [2,3]. Practically and contrary to preconceived ideas, the construction process of the sub-and super-solutions in the present work is broadly similar to the one used in the case of constant exponent problems (see, e.g., [7,18,19]), despite the loss of the homogeneity property of the operator ∆ p i (x) , which constitutes in itself a major obstacle to face. The crucial aspect of the argument is the new Mean Value Theorem (cf.…”