Zermelosystem
A Zermelosystem denotes a subset system in set theory and originates from Ernst Zermelo's proof of the comparability theorem .
A set is called a chain of subsets (⊆-chain) if:
A non-empty set is called a Zermelosystem if for all ⊆-chains in :
Be a Zermelosystem, it means a goal of when:
One can use the axiom of choice to prove that such a goal exists in any Zermelosystem.
- See also: mightiness
literature
- Oliver Deiser: Introduction to set theory . Berlin 2004 . ISBN 3-540-20401-6