Line graph of a hypergraph

Line graph of a hypergraph --- реберный граф гиперграфа.

The line graph [math]\displaystyle{ L({\mathcal H}) = ({\mathcal H}, E) }[/math] of a hypergraph [math]\displaystyle{ {\mathcal H} }[/math] is the intersection graph of [math]\displaystyle{ {\mathcal H} }[/math], i.e., [math]\displaystyle{ ee' \in E }[/math] if and only if [math]\displaystyle{ e \cap e' \neq \emptyset }[/math].