= Separating family of disjoint set pairs
A family $(A_i,B_i)_{i=1}^m$ of pairs of disjoint subsets of a finite set separates its points if each two distinct points lie on opposite sides of at least one pair. Empty sides are allowed by this definition. Let $d(x)$ count pairs containing $x$. Associate to $x$ the subcube of $\{0,1\}^m$ fixing coordinate $i$ to zero on $A_i$ and one on $B_i$. Separation makes these subcubes disjoint and yields the <disjoint subcube packing inequality>.
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