User blog comment:Rgetar/Square brackets OCF/@comment-35470197-20181204012327

> Rule 2

What does "contain" in this context mean? If it is just the usual set-theoretic inclusion, then the condition is equivalent to \(\alpha \geq X\). If you are refering to the inclusion of formal strings, then your function is not an OCF at all. It is just a notation system.

> Rule 3

It conflicts Rule 1 as long as you restrict it to the case \(X \neq I\). And then, you need to define what the "initial" ordinal \(I\) is.