On the completeness of normed spaces (Q979163)

The main problem being solved in the paper under review was already proposed by the reviewer in the Conference on Inequalities and Applications, which was held in Noszvaj-Hungary in 2007 [see Problem 3, page xlii, \textit{C. Bandle, A. Gilányi, L. Losonczi, Z. Páles} and \textit{M. Plum} (eds.), Inequalities and applications. International Series of Numerical Mathematics 157. Basel: Birkhäuser (2009; Zbl 1148.26004)]. At the same conference, it was solved in an elegant and short way. This solution, in a general form, can be found in \textit{R. Ger}, \textit{A. Gilanyi} and \textit{P. Volkmann} [Ann. Math. Silesianae 25 (2009), 112--113 (2010)].