Hypernested Block Hyper Notation (HBHN) is the 6th part of HN.
An expression is of the form H<n,A>, where n is the base and A is an array.
As always, definitions from NBHN apply here.
There are not much changes in the definition, but there is a big change in the growth rate.
We need to introduce a new block, called [X]. X is the biggest array, but only in HBHN. (X is also a cascader, but more on that in the next parts)
To solve A,[X],B, you just solve it like you would solve A,[B],B, except when A is 1 and B is a sequence array, then the FS can be calculated as follows:
First, take the WHOLE array (unless [X] is inside a block, then take the whole array inside of the block), and call it N.
Then, go back to 1,[X],B. Decrease B by 1, and this is the first member of the FS, which we will call FS(1). The second member of the FS, which we will call FS(2), will be 1,[N],[X],B-1. The (n+1)th member of the FS, which we will call FS(n+1), will be 1,[FS(n)],[X],B-1.
That's it.