New posts in Set Theory

Calculate the number of topologies on {1,2,...,n}

Write a program to perform set operations.

In ZF, if injection from A to B doesn't exist, then does surjection from A to B exist?

What does Cohen independence theorem say?

Can we always "locate" a transitive model inside some larger transitive model?

Cartesian product of two collections of sets?

Rank $ (a) {\aleph_4}^{\aleph_4}, (b) {\aleph_0}^{\aleph_4}, (c) {\aleph_4}^{\aleph_0}, (d) {\aleph_4}, (e) {\aleph_5}, (f) {\aleph_5}^{\aleph_0} $

In ZF, does the ring of continuous functions $C([0,1], \mathbb{R})$ have prime ideals which is not maximal?

What is wrong with this proof that inaccessible cardinals are inconsistent

Simple model-theoretic arguments in set theory