Cantor's theorem

Bigger than bijection

Cantor's theorem is the mathematical proof that for any set, the set of all its subsets (its power set) is strictly larger than the original set.

This holds even for infinite sets, establishing that infinities come in different sizes.

The theorem's diagonal argument shows that no set can be put into one-to-one correspondence with its power set.

cardinality

uncountable

Not able to enumerate

real numbers · natural numbers

Cantor

mathematician

Professional in abstract quantities

pioneer · infinity · ordinal numbers

proof

diagonalization

Reducing to diagonal form

logical reasoning · lemma · corollary · proof by contradiction · self-reference · function · mapping

foundations

set theory

Mathematics of abstract collections

Platonism

Categories
Opposites
set-theoretic results

Cantor's theoremcontinuum hypothesis

Claim about cardinal sizes

mathematical worldview

Cantor's theoremconstructivism

Active knowledge-building theory

intuitionism · formalism

countability status

Cantor's theoremcountability

Ability to be enumerated

Family

theorem

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Used worldwide · Timeless · Abstract · Rated G