Indicator function
= Indicator function
{title2=$\mathbf 1_E$}
{wiki}
The indicator function of a set $E$ is $\mathbf1_E(x)=1$ for $x\in E$ and $0$ otherwise.
= Indicator function
{title2=$\mathbf 1_E$}
{wiki}
The indicator function of a set $E$ is $\mathbf1_E(x)=1$ for $x\in E$ and $0$ otherwise.