>>13517092I do not have to "think" when I am already aware of the facts.
There are at least two different formal definitions in first order logic.
There are no sets in either, that would be silly, since sets are not needed.
When you make a construction in set theory, you check that the object
which you have constructed satisfies the formal definition. That is how it works,
necessarily. You can look up this kind of basic stuff for yourself.
