von Neumann ordinal
von Neumann ordinal
(mathematics)"Reasonable" set theories (like ZF) include Mostowski'sCollapsing Theorem: any well-ordered set is isomorphic toa von Neumann ordinal. In really screwy theories (e.g. NFU --New Foundations with Urelemente) this theorem is false.
The finite von Neumann ordinals are the von Neumann integers.