Inequalities for sums of powers (Q1105720)

Continuing his work on differences of powers (order reversed in the same issue of the same journal, see the review above) the author this time presents necessary conditions for \[ \prod^{n}_{k=1}(x^{a_ k}+y^{a_ k})^{q_ k}\geq 1\quad (\sum^{n}_{k=1}q_ k=0) \] and also shows that they are sufficient in the same special case as in the previous work. \{Note: It seems that in (i), on page 267, \(\leq\) should stand in place of =.\}