Given a set Un = {0, 1, ..., n− 1}, a collection M of subsets of Un that is closed under intersection and contains Un is known as a Moore family. The set of Moore families for a xed n is in bijection with the set of Moore co-families (union-closed families containing the empty set) denoted itself Mn. In this paper, we propose for the rst time a recursive de nition of the set of Moore co-familie...
