Please use code block syntax like this

func :: a
func = error "Your comment is ugly"

I am but a humble Ruby programmer trying to use the language best suited to the problem.

I think that n and u(n) being so "closely" related that saying "going to n" in the u sequence (... where a term of u is less than ...) or "going" to u(n) is the same, no? So I consider the issue as closed. If you don't agree please tell me. Thanks for your post.