Cardinal characteristic of the continuum
In the mathematical discipline of set theory, a cardinal characteristic of the continuum is an infinite cardinal number that may consistently lie strictly between ℵ 0 {\displaystyle \aleph _{0}} (the cardinality of the set of natural numbers), and the cardinality of the continuum, that is, the cardinality of the set R {\displaystyle \mathbb {R} } of all real numbers. The latter cardinal is denoted 2 ℵ 0 {\displaystyle 2^{\aleph _{0}}} or c {\displaystyle {\mathfrak {c}}} .
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