An Erd\H os--Ko--Rado theorem for cross $t$-intersecting families

Peter Frankl, Sang June Lee, Mark Siggers +1

Two families $\mathcal{A}$ and $\mathcal{B}$, of $k$-subsets of an $n$-set, are {\em cross $t$-intersecting} if for every choice of subsets $A\in \mathcal{A}$ and $B \in \mathcal{…