Tag Info


Filters (and ultrafilters) are used in various areas of mathematics, e.g. general topology, set theory, boolean algebras, model theory. In topology they can be used to study convergence in a more general way than just convergence of sequences.

Various types of ultrafilters (such as good ultrafilters, Ramsey ultrafilters, P-points) are useful in set theory and model theory and their applications.

history | show excerpt | excerpt history