Climb into Cantor’s Attic, where you will find infinities large and small. We aim to provide a comprehensive resource of information about all notions of mathematical infinity.

View the Project on GitHub neugierde/cantors-attic

**Quick navigation**

The upper attic

The middle attic

The lower attic

The parlour

The playroom

The library

The cellar

**Sources**

Cantor's Attic (original site)

Joel David Hamkins blog post about the Attic

Latest working snapshot at the wayback machine

This page will contain links to summary accounts of supporting foundational or background material used on the rest of the site.

You may like to begin in the playroom for an entertaining introduction to infinity.

Meanwhile, we expect that this page and these resources will be expanded as Cantor’s attic develops.

- Short informal presentation of the concept of infinity.
- The first steps towards infinity.

- transitive
- Basic Order Theory
- ordinal
- successor ordinal
- limit ordinal
- cardinality
- axiom of choice
- stationary, club
- Hereditary cardinality
- ultrafilter, measure
- ultrapower
- Partition property
- model

- Morse-Kelley set theory
- Zermelo-Fraenkel set theory
- Positive set theory
- Kripke-Platek set theory
- New Foundations