Helly hypergraph

Helly hypergraph --- гиперграф Хелли.

A hypergraph [math]\displaystyle{ {\mathcal H} }[/math] whose edges satisfy the Helly property; i.e., any subfamily [math]\displaystyle{ {\mathcal H}' \subseteq {\mathcal H} }[/math] of pairwise intersecting edges has a nonempty intersection.