Aleph-null

Full definition of aleph-null

Proper noun

1. (set theory) The first of the transfinite cardinal numbers; corresponds to the number of positive integers, also called natural numbers. Georg Cantor showed that even all the rational numbers could be put in one-to-one correspondence with them, and are therefore countable, enumerable or denumerable.

Synonyms

• (first transfinite cardinal number) aleph-naught, aleph-nought, aleph-zero, ℵ₀

Related terms

• aleph-one