This is a subspecies of BEAF.
I have wanted an easy notation that I can understand.
I think the easiest way to make a big number is "piling up."
So, I will make a piling-up notation.
Now, you need to understand that the default of PU is 1.
In math language,
I piled up b's. What's next? Piling up c's. Therefore,
Next, I can think the same thing:
(note: this approximation is just shows level. Since I know chain notation, I can think (how big PU is) better.)
Now, I will jump to polynominal. K means some one's.
I think this is as big as in extended chain notation, but I don't know how big it is exactly.