User blog comment:Koteitan/Categorizing of the rule sets for all sub versions of bashicu matrix/@comment-11227630-20191124074442

In BM3.3 and the introduction page, it seems that there is no refer to "row y-r", meaning that the \(a_{P_y(r+x)y-r}\) might be \(a_{P_y(r+x)y}\).