Lupanov's (k, s)-representation, named after Oleg Lupanov, is a way of representing Boolean circuits so as to show that the reciprocal of the Shannon effect. Shannon had showed that almost all Boolean functions of n variables need a circuit of size at least 2nn−1. The reciprocal is that: All Boolean functions of n variables can be computed with a circuit of at most 2nn−1 + o(2nn−1) gates.