Cardinality of the continuum

In set theory, the cardinality of the continuum is the cardinality or “size” of the set of real numbers ${\displaystyle \mathbb {R} }$, sometimes called the continuum. It is an infinite cardinal number and is denoted by ${\displaystyle |\mathbb {R} |}$ or ${\displaystyle {\mathfrak {c}}}$ (a lowercase fraktur script "c").

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