countably infinite set

countably infinite set

[′kau̇nt·ə·blē ‚in·fə·nət ′set]
(mathematics)
References in periodicals archive ?
1] can be expressed as a disjoint union of a class C of countably infinite sets, the cardinality of C being [[omega].
40, a set X being infinite, it can be expressed as a disjoint union of a class C of countably infinite sets that is, each of which has cardinality [omega].