User blog comment:Vel!/Googology and well-defined-ness/@comment-1605058-20141007094943/@comment-10429372-20141011065534

The thing with BEAF is that it is not B or even C, the upper regions are D. Therefore, we can only guess things. For example, should {X,X/2}&n be an structure? Are we using the LVO or the larger version of the & operator?

@Peng, that was an 'if'. 'If dollar function has no rule saying us when to drop $, then it would be ill defined (officially), though I've fixed it years ago. (well, it should be more than a year, before I finally got what you meant by 'there is no rule about when $ dissappears')