User blog comment:Primussupremus/the next step in my notation./@comment-73.235.194.108-20170429200314

I see. Looks a lot like your old notation. Here is something you can think about. [a,b,c|d] recurses [a,b,c]. But how can we recurse [a,b,c|d]? I am suggesting that [a,b,c|d,k] for some constant k should recurse [a,b,c|d,k-1]. This should get you much farther than your previous notation.