Symbols:Set Theory/Cardinality

Cardinality

 * $\card S$

The cardinality of the set $S$.

For finite sets, this means the number of elements in $S$.

Also see
See:
 * Symbols:Absolute Value
 * Symbols:Complex Modulus
 * Symbols:Order of Structure
 * Symbols:Order of Group Element

for other uses of this symbol.