nLab size issues




The basis of it all

 Set theory

set theory

Foundational axioms

foundational axioms

Removing axioms



There are various ways to deal with size issues in the foundations of mathematics. All of them involve the notion of universe in one way or another.

In any case, given a universe UU, we say that a collection is UU-small if it is in UU, a collection is UU-large if it is not in UU, any subcollection of UU is a class, and a subcollection of UU is a proper class if it is not a singleton subcollection of UU.

See also

Last revised on November 19, 2022 at 17:04:00. See the history of this page for a list of all contributions to it.