User blog comment:Chronolegends/Numbers in CSBN/@comment-25601061-20161022141705/@comment-29014792-20161022202012

How about:


 * [a[0]2b] = [a][b]
 * [#[0]2b] = [#][b]
 * [0[1]20] = Limit of level 1
 * [0[0]20[1]20] = [0[0[...]0[1]20]0[1]20]
 * [0[1]21] = [0[0]20[0]20[0]2...[1]20]