# Lupanov representation

Let A1, ..., Ap be a partition of the rows of this table such that for i < p, |Ai = s and $|A_p|=s'\leq s$. Let ƒi(x) = ƒ(x) iff x ∈ Ai.
Moreover, let $B_{i,w}$ be the set of the columns whose intersection with $A_i$ is $w$.