User blog comment:Wythagoras/Dollar function formal definition/@comment-5529393-20130616091711/@comment-10429372-20130616094943

even a$0]_[0 reach level f_phi(omega,0)+1

Dont forget that for example a$[0]_([0][0]) = a$[0]_(a[0]) =

a$[0]_(a-1[0])  [0]_(a-1[0])  ... [0]_(a-1[0])  [0]_(a-1[0]) is not a$[0]_(2a) if there are numbers that are not in brackets you must solve them first. That allows for subscript and non-subscript.