Abstract: | ![Ocy](/content/u486126667665078/xxlarge1054.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![vcy](/content/u486126667665078/xxlarge1074.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![zcy](/content/u486126667665078/xxlarge1079.gif) ![ucy](/content/u486126667665078/xxlarge1091.gif) ![lcy](/content/u486126667665078/xxlarge1083.gif) ![softcy](/content/u486126667665078/xxlarge1100.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![acy](/content/u486126667665078/xxlarge1072.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![acy](/content/u486126667665078/xxlarge1072.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![softcy](/content/u486126667665078/xxlarge1100.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![chcy](/content/u486126667665078/xxlarge1095.gif) ![dcy](/content/u486126667665078/xxlarge1076.gif) ![lcy](/content/u486126667665078/xxlarge1083.gif) ![lcy](/content/u486126667665078/xxlarge1083.gif) ![yucy](/content/u486126667665078/xxlarge1102.gif) ![bcy](/content/u486126667665078/xxlarge1073.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![fcy](/content/u486126667665078/xxlarge1092.gif) ![ucy](/content/u486126667665078/xxlarge1091.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![kcy](/content/u486126667665078/xxlarge1082.gif) ![tscy](/content/u486126667665078/xxlarge1094.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![dcy](/content/u486126667665078/xxlarge1076.gif) ![vcy](/content/u486126667665078/xxlarge1074.gif) ![ucy](/content/u486126667665078/xxlarge1091.gif) ![pcy](/content/u486126667665078/xxlarge1087.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![mcy](/content/u486126667665078/xxlarge1084.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ycy](/content/u486126667665078/xxlarge1099.gif) f(x,y) 0BV(T2), ![gcy](/content/u486126667665078/xxlarge1075.gif) ![dcy](/content/u486126667665078/xxlarge1076.gif) ![Lambda](/content/u486126667665078/xxlarge923.gif) ={1/ n}
n=1
![scy](/content/u486126667665078/xxlarge1089.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![chcy](/content/u486126667665078/xxlarge1095.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![kcy](/content/u486126667665078/xxlarge1082.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![chcy](/content/u486126667665078/xxlarge1095.gif) ![acy](/content/u486126667665078/xxlarge1072.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![tcy](/content/u486126667665078/xxlarge1090.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![chcy](/content/u486126667665078/xxlarge1095.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ycy](/content/u486126667665078/xxlarge1099.gif) ![scy](/content/u486126667665078/xxlarge1089.gif) ![ucy](/content/u486126667665078/xxlarge1091.gif) ![mcy](/content/u486126667665078/xxlarge1084.gif) ![mcy](/content/u486126667665078/xxlarge1084.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![yacy](/content/u486126667665078/xxlarge1103.gif) ![dcy](/content/u486126667665078/xxlarge1076.gif) ![Fcy](/content/u486126667665078/xxlarge1060.gif) ![ucy](/content/u486126667665078/xxlarge1091.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![softcy](/content/u486126667665078/xxlarge1100.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![acy](/content/u486126667665078/xxlarge1072.gif) ![vcy](/content/u486126667665078/xxlarge1074.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![mcy](/content/u486126667665078/xxlarge1084.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![ocy](/content/u486126667665078/xxlarge1086.gif) ![gcy](/content/u486126667665078/xxlarge1075.gif) ![rcy](/content/u486126667665078/xxlarge1088.gif) ![acy](/content/u486126667665078/xxlarge1072.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) ![icy](/content/u486126667665078/xxlarge1080.gif) ![chcy](/content/u486126667665078/xxlarge1095.gif) ![iecy](/content/u486126667665078/xxlarge1077.gif) ![ncy](/content/u486126667665078/xxlarge1085.gif) .
Dedicated to Professor Károly Tandori, the outstanding mathematician and academician on his seventieth birthday This work was done under the financial support of the Russian Foundation for Fundamental Scientific Research, Grant 93-01-00240. |