 To characterize the SR model more precisely we need the notion of a homogenous partition. A homogenous partition of \(A\) is a set of subclasses or cells \(C_i\) of \(A\) that are mutually exclusive and exhaustive, where \(P(B\pmid A.C_i) \ne P(B\pmid A.C_j)\) for all \(C_i \ne C_j\) and where no further statistically relevant partition of any of the cells \(A\), \(C_i\) can be made with respect to \(B\)—that is, there are no additional attributes \(D_k\) in \(A\) such that 