Infinite set: Difference between revisions

Content deleted Content added
Citation bot (talk | contribs)
Add: encyclopedia. Removed parameters. Some additions/deletions were parameter name changes. | Use this bot. Report bugs. | Suggested by Whoop whoop pull up | #UCB_webform 1431/2173
Line 6:
 
==Properties==
The set of [[natural numbers]] (whose existence is postulated by the [[axiom of infinity]]) is infinite.<ref name=":0" /><ref>{{Citation|last=Bagaria|first=Joan|title=Set Theory|date=2019|url=https://plato.stanford.edu/archives/fall2019/entries/set-theory/|workencyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Fall 2019|publisher=Metaphysics Research Lab, Stanford University|access-date=2019-11-30}}</ref> It is the only set that is directly required by the [[axiom]]s to be infinite. The existence of any other infinite set can be proved in [[Zermelo–Fraenkel set theory]] (ZFC), but only by showing that it follows from the existence of the natural numbers.
 
A set is infinite if and only if for every natural number, the set has a [[subset]] whose [[cardinality]] is that natural number.{{cn|date=August 2020}}