Equinumerosity

From Wiki @ Karl Jones dot com
Revision as of 09:20, 22 September 2016 by Karl Jones (Talk | contribs) (Created page with "In mathematics, two sets A and B are '''equinumerous''' if there exists a one-to-one correspondence (a bijection) between them, i.e. if there exi...")

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

In mathematics, two sets A and B are equinumerous if there exists a one-to-one correspondence (a bijection) between them, i.e. if there exists a function from A to B such that for every element y of B there is exactly one element x of A with f(x) = y.

Description

Equinumerous finite sets have the same number of elements. The definition of equinumerosity using bijections can be applied to both finite and infinite sets and allows one to state whether two sets have the same size even if they are infinite.

Unlike finite sets, some infinite sets are equinumerous to proper subsets of themselves.

Equinumerous sets are said to have the same cardinality.

See also

External links