User blog comment:Wythagoras/Dollar function part 2/@comment-1605058-20130607193802

I noticed blank in   \([0\text{ }\bullet]\) and   \([b+1\text{ }\bullet]\)  in rules 2 and 3 can be considered level 1 separators, and commas in later rules as level 2 separators. I wonder if you can possibly extend it by adding higher-order separators.