User blog comment:Wythagoras/All my stuff/@comment-10429372-20130718073726/@comment-5529393-20130718155206

Dr. Ceasium, the z function would cause a problem for the iota function as well, if it was an allowable function. Presumably you solve this by not allowing a function like z in your function set. Well, the ¥ function can do the same thing, can't it? What's good for the goose is good for the gander.

I'm not sure why you say "the z function does not refer to any kind of definability function". The z function clearly refers to the notion of definability, and so would be out of bounds, at least in my version of the ¥ function, and I presume it would be for the iota function as well.