Cardinality of Set of Subsets/Also denoted as

Theorem

The number of subsets of cardinality $m$ that can be taken from a set of cardinality $n$ can also be seen as:

${}_n C_m$

${}^n C_m$

${C_n}^m$

In order to avoid any ambiguity, $\mathsf{Pr} \infty \mathsf{fWiki}$ will tend to use $\dbinom n m$.

Sources

• 1953: L. Harwood Clarke: A Note Book in Pure Mathematics ... (previous) ... (next): $\text I$. Algebra: Permutations and Combinations
• 1964: A.M. Yaglom and I.M. Yaglom: Challenging Mathematical Problems With Elementary Solutions: Volume $\text { I }$ ... (previous) ... (next): Problems
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): selection