Both Djordjević (2007) and Takane et al. (2007) have studied the equivalent conditions for and . In this note, we derive the necessary and sufficient conditions for , , and .
To access the full article, please see PDF.
College of Mathematics and Statistics, Chongqing University, Chongqing 400030, China
Journal of Inequalities and Applications 2010, 2010:312767 doi:10.1155/2010/312767
The electronic version of this article is the complete one and can be found online at: http://www.journalofinequalitiesandapplications.com/content/2010/1/312767
|Received:||28 October 2009|
|Accepted:||16 April 2010|
|Published:||24 May 2010|
© 2010 The Author(s).
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.