User blog comment:Vel!/Factoid notation/@comment-5150073-20130523164040/@comment-5150073-20130524195831

I found that ! ~ n^^^n. If it is indeed true, then probably ! ~ n^^^^n, ! ~ n^^^^^n, so each increment to the separator-level increases the number of up-arrows. I think it means that factoid notation catches up BEAF on tetrational arrays.