Lower attic

Welcome to the lower attic, where we store the comparatively smaller notions of infinity. Roughly speaking, this is the realm of countable ordinals and their friends.

• Up to The middle attic

• $\omega_1^x$
• admissible ordinals
• $\Gamma$
• $\omega_1^{ck}$
• $\epsilon_0$, $\epsilon_1$ and the $\epsilon_\alpha$ hierarchy
• small countably infinite ordinals
• Hilbert's hotel
• [[\(\omega\)]]