TITLE: How to denote the opposite case of the Kronecker Delta?
QUESTION [7 upvotes]: The Kronecker delta is defined as link to wikipedia: 
$$\delta_{l,m} = \begin{cases}
1 & \text{if }m=l,\\
0 & \text{if }m\neq l.
\end{cases}$$
I would like to denote the case where:
$$ = \begin{cases}
0 & \text{if }m=l,\\
1 & \text{if }m\neq l.
\end{cases}$$
How should this be done?

REPLY [6 votes]: Another possibility would be to use the Iverson bracket. For example, the Kronecker delta is $\delta_{l, m} = [l = m]$, while your "opposite case of the Kronecker delta" would just be $[l \neq m]$.