infinite set
infinite set
[′in·fə·nət ′set]infinite set
(mathematics)(i) ("Dedekind infinite") A set X is infinite if there existsa bijection (one-to-one mapping) between X and some propersubset of X.
(ii) A set X is infinite if there exists an injection from N(the set of natural numbers) to X.
In the presence of the Axiom of Choice all such definitionsare equivalent.