\begin{definition}[Definition:Pairwise Disjoint/Set of Sets]
A set of sets $\Bbb S$ is said to be '''pairwise disjoint''' {{iff}}:
:$\forall X, Y \in \Bbb S: X \ne Y \implies X \cap Y = \O$
Here, $\cap$ denotes intersection, and $\O$ denotes the empty set.
Hence we can say that the elements of $\Bbb S$ are '''pairwise disjoint'''.
\end{definition}