Characteristic vector of a set
= Characteristic vector of a set
{title2=$\mathbf 1_A$}
For $A\subseteq[n]$, the characteristic vector $\mathbf1_A\in\{0,1\}^n$ has coordinate $i$ equal to one exactly when $i\in A$. Under this identification, <set union> becomes coordinatewise Boolean OR.
= Characteristic vectors of sets
{synonym}