Partition-crossing hypergraphs

Csilla Bujtás, Zsolt Tuza

For a finite set $X$, we say that a set $H\subseteq X$ crosses a partition $\mathcal{P}=(X_1,\dots ,X_k)$ of $X$ if $H$ intersects $\min (|H|,k)$ partition classes. If $|H|\ge k$, thi…