User blog comment:Cookiefonster/My informal proposal of BEAF from limit of tetrational arrays up to SVO/@comment-5150073-20140920170843/@comment-5150073-20140927070029

It's one of a few things on which we can rely in study of BEAF. Also, "X" isn't supposed to be infinite - it's a "variable" which represent growth rates. X^^(X+1) should be a power tower of X's with X+1 terms high and not just (X^^X)^(X^^X) or so.