User blog comment:Wythagoras/Dollar function formal definition/@comment-5529393-20130619005520/@comment-5529393-20130619220259

Wythagoras modified his notation in between our posts - originally there was an "a" in the RHS of rule 9.

I assumed that [...]_1 is the same as [...]. Also, I added commas since it improved the notation - the commas didn't affect the circularity.