PNG  IHDR=&]0PLTE@@@ftRNSS pHYsetEXtTitleInftyEditor MathImageytEXtAuthorAdministrator*"tEXtDescription $ {\bm{x}_{\bm{r}}} $mtEXtCopyrightInftyProject@$tEXtCreation Time r'rr'rr IDATx P @ (Ig*Tb\ܒ'̠{W