cardinality

mathematics The number of elements in a set. If two sets

have the same number of elements (i.e. there is a bijection

between them) then they have the same cardinality. A

cardinality is thus an isomorphism class in the category

of sets.

aleph 0 is defined as the cardinality of the first

infinite ordinal, omega (the number of naturalnumbers).

(1995-03-29)